Radiation-sensitive composition of chemical amplification type

ABSTRACT

Disclosed is a chemically amplified radiation sensitive composition containing a hydroxystyrene resin and an onium salt precursor which generates a fluorinated alkanesulfonic acid as a photoacid generator, wherein the photoacid generator is a sulfonium or iodonium salt of a fluorinated alkane sulfonic acid, represented by formula (I): 
     
       
         Y + ASO 3   −   (I) 
       
     
     wherein A represents CF 3 CHFCF 2  or CF 3 CF 2 CF 2 CF 2 ; and Y represents                    
     wherein R 1 , R 2 , R 3 , R 4 , and R 5  each independently represent an alkyl group, a monocyclic or bicyclic alkyl group, a cyclic alkylcarbonyl group, a phenyl group, a naphthyl group, an anthryl group, a peryl group, a pyryl group, a thienyl group, an aralkyl group, or an arylcarbonylmethylene group, or any two of R 1 , R 2 , and R 3  or R 4  and R 5  together represent an alkylene or an oxyalkylene which forms a five- or six-membered ring together with the interposing sulfur or iodine, said ring being optionally condensed with aryl groups.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chemically amplified radiationsensitive composition, and more particularly to the so-called“photoresist” for the manufacture of electronic components, printingplates, and three-dimensional micro objects.

2. Background Art

An increase in the processor speed attained by the development ofmicroelectronic devices with higher integration density in theelectronic industry has lead to a demand for further improved radiationsensitive compositions. That is, an improvement in properties, such asresolution of photoresists and dimensional accuracy of images, has beenrequired for satisfying demands in the microelectronic device productionindustry.

According to the Rayleigh's equation

R=k₁*λ/NA

wherein R denotes the ultimate resolution, k₁ is a constant, λ is thewavelength of the light source used in exposure, and NA is the numericalaperture of the illuminating optical system, use of a light sourcehaving shorter wavelength in exposure can most effectively enhance theultimate resolution. This has been effectively applied to the transitionof irradiation technology from g-line (436 nm) to i-line (365 nm), andhas pushed the resolution limits of conventional near UV irradiationtechnology to below 0.30 μm. With the need to produce even smallerfeatures, shorter wavelength radiation, such as deep UV (DUV) radiation(150-320 nm), has become employed. Photons generated from DUV radiationexhibit higher energy than those generated from near UV radiationsources. Therefore, the number of photons per unit energy is smaller,leading to a demand for radiation sensitive compositions with highersensitivity.

Radiation sensitive compositions called “chemically amplifiedphotoresists” are known in the art, and are advantageous in that thecatalytic imaging process can provide high photosensitivity. By virtueof high photosensitivity and high resolution, the chemically amplifiedradiation sensitive compositions are being substituted for conventionalradiation sensitive compositions and being spread. The chemicallyamplified radiation sensitive compositions comprise a radiationsensitive acid generating agent (photoacid generator; hereinafter oftenreferred to as “PAG”) which generates an acid. Upon exposure, this PAGreleases an acid which catalyzes a layer dissolution reaction in thecase of positive-working photoresists and catalyzes a crosslinkingreaction in the case of negative-working photoresists.

Positive-working chemically amplified photoresists are the so-called“two component systems” which basically comprise: (1) a resin which hasbeen rendered insoluble in alkaline solutions by masking at least a partof the water soluble groups on the resin with an acid cleavableprotective group; and (2) a PAG. Optionally, low molecular weight orphenol derivatives masked with acid cleavable protective groupsdescribed below are added to further improve the lithographicperformance. This system is known as a “three component chemicallyamplified radiation sensitive composition. Upon exposure, the PAGproduces a strong acid capable of cleaving the bond between protectivegroup and the resin, resulting in the formation of an alkali-solubleresin. Acid molecules produced from the PAG upon exposure are notconsumed by a single reaction for cleaving the protective group from theresin, and one acid molecule produced during the exposure can cleave alarge number of protective groups from the resin. This contributes tothe high sensitivity of chemically amplified radiation sensitivecompositions.

Many two or three component positive-working photoresist compositionscomprising polyhydroxystyrene resins or phenol derivatives havingpolyfunctional groups have been described in patents and literature. Inthe case of positive-working two component photoresist compositions, thephenolic groups of the polymer are partly or fully protected byacid-cleavable protective groups, for example, t-butoxycarbonyl groups(U.S. Pat No. 4,491,628), t-butoxycarbonylmethyl groups (U.S. Pat. No.5,403,695), t-butyl groups, trimethylsilyl groups, tetrahydropyranylgroups (U.S. Pat. No. 5,350,660), 2-(alkoxyethyl) groups (U.S. Pat. No.5,468,589 and U.S. Pat. No. 5,558,971, and U.S. Pat. No. 5,558,976), orcombinations thereof. A co- or terpolymer of hydroxystyrene with(meth)acrylic acid, wherein the carboxylic acid is partly or fullyprotected by acid-cleavable groups, such as t-butyl groups (U.S. Pat.No. 4,491,628, U.S. Pat. No. 5,482,816, and U.S. Pat. No. 5,492,793),amyl groups, or tetrahydropyranyl groups, has also been regarded asuseful for positive-working two component photoresist compositions. Theaddition of dissolution inhibitors, which have been protected in thesame manner as described above, to the positive-working photoresistcomposition is described in U.S. Pat. No. 5,512,417 and U.S. Pat. No.5,599,949.

In the case of negative-working photoresists, a crosslinking agent, suchas hexamethoxy methylmelamine, is added to an alkali soluble phenolicresin (U.S. Pat. No. 5,376,504 and U.S. Pat. No. 5,389,491). The acidproduced from the PAG upon exposure induces a crosslinking reaction inthe exposed areas.

As is apparent from the foregoing description, PAG plays an importantrole in the imaging process for both positive-working andnegative-working chemically amplified resists, because PAG governs lightresponse properties, such as absorption of light or quantum yield ofacid formation, and, in addition, governs the properties of the producedacid, such as acid strength, mobility, or volatility. Useful PAGs forboth positive-working and negative-working chemically amplified resistsinclude ionic onium salts, particularly iodonium salts or sulfoniumsalts with strong non-nucleophilic anions (U.S. Pat. No. 4,058,400 andU.S. Pat. No. 4,933,377), for example, hexafluoroantimonate andtrifluoromethane sulfonate (U.S. Pat. No. 5,569,784) oraliphatic/aromatic sulfonates (U.S. Pat. No. 5,624,787). In addition,many non-ionic PAGs producing the above mentioned sulfonic acids havebeen described for both positive-working and negative-working chemicallyamplified photoresist materials (U.S. Pat. No. 5,286,867 and U.S. Pat.No. 5,338,641). Further, certain hydrogen halide producing PAGs havebeen suggested for advantageous use in negative-working chemicallyamplified resists (U.S. Pat. No. 5,599,949).

U.S. Pat. No. 5,731,364 discloses that binulear sulfonium compoundshaving perfluoroaryl sulfonate and perfluoroalkyl sulfonate are usefulfor the image formation of positive-working and negative-workingphotoresists.

This patent, however, does not suggest specific superiority in use ofsulfonium compounds of nonafluorobutane sulfonate as PAGs in combinationwith hydroxystyrene based resin having a protective group which can beeliminated with an acid.

Among these PAGs, those onium salts producing trifluoromethane sulfonicacids upon exposure are particularly preferred, because superiorsensitivity and good ultimate resolution of the photoresist system canbe obtained. In addition, these PAGs are known to reduce the formationof insolubles on the substrate or at the substrate/resist interfaceknown as scum.

It was found, however, that minor quantities of the rather volatiletrifluoromethane sulfonic acid (TFSA) produced during the irradiationprocess may evaporate (outgas) from the photoresist film and causecorrosion of the exposure and process equipment. The same trouble isobserved when hydrogen halide producing PAGs are used. It may beanticipated that a long time exposure especially to the evaporatingfumes of the volatile, aggressive TFSA may cause hazards to the healthof the labor force. In addition, it is known that resist materialscontaining PAGs which produce TFSA tend to produce the so-calledT-shaped pattern profiles, and show linewidth changes upon processdelays (i.e. inadequate delay time stability) due to the high volatilityand the diffusion properties of this acid. Attempts to identify anadequate replacement for TFSA, or its onium salt precursors,respectively, were so far not very successful, because deterioration ofthe resist performance, i.e. of resolution capability, or sensitivityoccurred.

An evaluation of a chemically amplified resist system using a largenumber of sulfonic acids producing onium salt precursors has revealedthat most acids yielding good resolution are poor in sensitivity, whilethose compounds, which yield high sensitive resists do not perform verywell in terms of resolution. More specifically, it was found thatlow-molecular weight aliphatic and some aromatic sulfonic acids havehigh vapor pressures, thus causing the above mentioned corrosion of theequipment, forming T-topped photoresist profiles, and yieldingsignificant linewidth changes upon process time delays, while largermolecular weight aliphatic and aromatic sulfonic acids do not providethe required sensitivity, or have inadequate resolution power.

SUMMARY OF THE INVENTION

The present inventors have made extensive and intensive studies onimproved chemically amplified resist materials for production ofsemiconductors, particularly chemically amplified resist materials whichare less likely to cause corrosion of equipment by outgassing and, atthe same time, has good sensitivity and resolution. As a result, thepresent inventors have now found that a combination of a film forminghydroxystyrene based resin with an onium salt precursor capable ofgenerating a fluorinated alkanesulfonic acid as a photoacid generatorcan provide an excellent chemically amplified radiation sensitivecomposition. The present invention has been made based on such finding.

Accordingly, it is an object of the present invention to provide achemically amplified radiation sensitive composition which is lesslikely to cause the corrosion of the equipment, T-topped photoresistprofiles, and significant linewidth changes upon process time delays.

It is another object of the present invention to provide a chemicallyamplified radiation sensitive composition which can realize highsensitivity and resolution, good pattern shapes and stability thereof.

It is still another object of the present invention to provide achemicaqlly amplified radiation sensitive composition containing aphotoacid generator which, by virtue of the generation of a nonvolatileacid, can eliminate problems associated with outgassing.

It is a further object of the present invention to provide a recordingmedium containing the chemically amplified radiation sensitivecomposition according to the present invention and to provide a processfor producing the recording medium.

The chemically amplified radiation sensitive composition according tothe present invention comprises at least

an onium salt precursor which generates a fluorinated alkanesulfonicacid as a photoacid generator and

a film forming hydroxystyrene based resin.

According to a preferred embodiment of the present invention, there isprovided a positive-working chemically amplified radiation sensitivecomposition, as a first aspect of the present invention, comprising:

(1) an onium salt precursor which generates a fluorinated alkanesulfonicacid as a photoacid generator;

(2) a film forming hydroxystyrene based resin which is is made alkaliinsoluble by protecting alkali soluble groups on the resin with an acidcleavable protective group; and

(3) optionally a dissolution inhibitor having at least one acidcleavable C—O—C or C—O—Si bonds.

According to a second aspect of the present invention, there is provideda negative-working chemically amplified radiation sensitive compositioncomprising:

(1) an onium salt precursor which generates a fluorinated alkanesulfonicacid as a photoacid generator;

(2) an alkali soluble film forming hydroxystyrene based resin; and

(3) optionally an acid-sensitive crosslinking agent.

According to a third aspect of the present invention, there is provideda radiation sensitive recording medium comprising: a substrate; and aradiation sensitive layer provided on the substrate, the radiationsensitive comprising the composition of the present invention.

According to a fourth aspect of the present invention, here is provideda process for producing a radiation sensitive recording medium,comprising the steps of: dissolving the composition of the presentinvention in a solvent; coating the solution onto a substrate to form aradiation sensitive layer; and removing the solvent by evaporation.

PREFERRED EMBODIMENTS OF THE INVENTION Chemically Amplified RadiationSensitive Composition

The chemically amplified radiation sensitive composition according tothe present invention basically comprises a film forming hydroxystyrenebased resin and an onium salt precursor which generates a fluorinatedalkanesulfonate as a photoacid generator.

According to the chemically amplified radiation sensitive composition ofthe present invention, the fluorinated alkanesulfonic acid generatedfrom the onium salt precursor upon exposure can significantly improvethe performance of the chemically amplified radiation sensitivecomposition containing a hydroxystyrene based resin in terms of imageformation, that is, resolution, dense/isolated line bias, dimensionalaccuracy of images, delay time stability, a reduction in volatilecomponents (outgas) and the like.

Surprisingly, the onium salt of a fluorinated alkanesulfonic acid as thephotoacid generator, when used in a (a) positive-working or (b)negative-working hydroxystyrene based chemically amplified radiationsensitive composition, can provide radiation sensitivity equal to thatin the case of the corresponding trifluoromethane sulfonate derivatives.Further, use of the photoacid generator according to the presentinvention provides substantially the same resolution and, in addition,does not form any scum. Further, surprisingly, better (rectangular)pattern profile accuracy, and less line surface and edge roughness areobserved. Due to the low vapor pressure of the fluorinatedalkanesulfonic acid, the evaporation tendency of this compound is almostnegligible at typical photoresist process temperatures (up to about 150°C.), thus eliminating both the formation of T-tops and the risk ofequipment corrosion. In addition, linewidth changes are minimized, asthe mobility and thus the diffusion range of the comparatively largemolecular weight fluorinated alkanesulfonic acid in chemically amplifiedradiation sensitive films are smaller than that oftrifluoromethanesulfonic acid. The reduced mobility has a positiveeffect on the dense lines to isolated line bias; i.e. the linewidthdimensions of isolated lines and dense lines are almost equal at a givenexposure dose. Therefore, the use of the onium salts of the presentinvention very advantageously contributes in several important ways tothe overall performance of (a) positive-working and (b) negative-workinghydroxystyrene based chemically amplified radiation sensitivecompositions, as well as to the life-time and maintenance of theequipment employed, and to the health of the work forces.

(a) Photoacid Generator

The photoacid generator used in the compositon of the present inventionis an onium salt precursor which generates a fluorinated alkanesulfonicacid. The onium salt precursor is not particularly limited so far as itcan generate a fluorinated alkanesulfonic acid. According to a preferredembodiment the present invention, the onium salt precursor is asulfonium salt or an iodonium salt.

The fluorinated alkanesulfonic acid also is not particularly limited.Preferably, the fluorinated alkanesulfonic acid is such that thealkanesulfonic acid has 3 to 4 carbon atoms.

Preferred onium salt precursors, which generate fluorinatedalkanesulfonic acids, include sulfonium salts or iodonium salts of3,3,3,3,1,1-hexafluoropropanesulonate and nonafluorobutanesulonic acid.

According to a more preferred embodiment of the present invention, theonium salt precursor, which generates a fluorinated alkanesulfonic acid,is a sulfonium or iodonium salt of a fluorinated alkane sulfonate offormula (I):

Y⁺ASO₃ ⁻  (I)

wherein A represents CF₃CHFCF₂ or CF₃CF₂CF₂CF₂; and

Y represents

wherein R¹, R² , R³, R⁴, and R⁵ each independently represent

an alkyl group,

a monocyclic or bicyclic alkyl group,

a cyclic alkylcarbonyl group,

a phenyl group,

a naphthyl group,

an anthryl group,

a peryl group,

a pyryl group,

a thienyl group,

an aralkyl group, or

an arylcarbonylmethylene group, or

any two of R¹, R², and R³ or R⁴ and R⁵ together represent an alkylene oran oxyalkylene which forms a five- or six-membered ring together withthe interposing sulfur or iodine, said ring being optionally condensedwith aryl groups,

one or more hydrogen atoms of R¹, R², R³, R⁴, and R⁵ being optionallysubstituted by one or more groups selected from the group consisting ofa halogen atom, an alkyl group, a cyclic alkyl group, an alkoxy group, acyclic alkoxy group, a dialkylamino group, a dicyclic dialkylaminogroup, a hydroxyl group, a cyano group, a nitro group, an aryl group, anaryloxy group, an arylthio group, and groups of formulae (II) to (VI):

wherein R⁶ and R⁷ each independently represent a hydrogen atom, an alkylgroup, which may be substituted by one or more halogen atoms, or acyclic alkyl group, which may be substituted by one or more halogenatoms, or R⁶ and R⁷ together can represent an alkylene group to form aring,

R⁸ represents an alkyl group, a cyclic alkyl group, or an aralkyl group,or R⁶ and R⁸ together represent an alkylene group which forms a ringtogether with the interposing —C—O— group, the carbon atom in the ringbeing optionally substituted by an oxygen atom,

R⁹ represents an alkyl group or a cyclic alkyl group, one or two carbonatoms in the alkyl group or the cyclic alkyl group being optionallysubstituted by an oxygen atom, an aryl group, or an aralkyl group,

R¹⁰ and R¹¹ each independently represent a hydrogen atom, an alkylgroup, or a cyclic alkyl group,

R¹²represents an alkyl group, a cyclic alkyl group, an aryl group, or anaralkyl group, and

R¹³ represents an alkyl group, a cyclic alkyl group, an aryl group, anaralkyl group, the group —Si(R¹²)₂R¹³, or the group —O—Si(R¹²)₂R¹³.

The compound represented by formula (I) is advantageous in that it hasgood solubility in general solvents used in radiation sensitivecompositions and, in addition, has good affinity for the componentscontained in the radiation sensitive composition.

In formula (I), the alkyl group as a group or a part of a group may beof straight chain type or branched chain type. The halogen refers to afluorine, chlorine, bromine, or iodine atom. The aralkyl refers tobenzyl, phenylethyl (phenetyl), methylbenzyl, naphthylmethyl or thelike. The aryl preferably refers to phenyl, naphthyl, tolyl or the like.

According to a preferred embodiment of the present invention, a group ofpreferred compounds represented by formula (I) are those wherein

R¹, R², R³, R⁴, and R⁵ each independently represent

a C₁₋₁₂ alkyl group (preferably a C₁₋₆ alkyl group, more preferably aC₁₋₃ alkyl group),

a C₆₋₁₂ monocyclic or bicyclic alkyl group (preferably C₃₋₆ monocyclicalkyl group or a C₁₀₋₁₂ bicyclic alkyl group),

a C₄₋₁₂ cyclic alkylcarbonyl group (preferably a C₃₋₆ monocyclicalkylcarbonyl group),

a phenyl group,

a naphtyl group,

an anthryl group,

a peryl group,

a pyryl group,

a thienyl group,

an aralkyl group, or

an arylcarbonylmethylene group with up to 15 carbon atoms, or

any two of R¹, R², and R³, or R⁴ and R⁵ together represent an alkyleneor an oxyalkylene which forms a five- or six-membered ring together withthe interposing sulfur or iodine atom, said ring being optionallycondensed with aryl groups.

According to a more preferred embodiment of the present invention, thecompounds represented by formula (I) are those wherein

one or more hydrogen atoms of R¹, R², R³, R⁴, and R⁵ are substituted byat least one group selected from the group consisting of a halogen atom,a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, a C₁₋₆ alkoxy group, aC₃₋₆ cyclic alkoxy group, a di-C₁₋₃ alkylamino group, a cyclic di-C₆₋₁₂alkylamino group, a hydroxyl group, a cyano group, a nitro group, anaryl group, an aryloxy group, an arylthio group, and groups representedby formulae (II) to (VI). Further, compounds are preferably utilizedwherein, in the groups represented by formulae (II) to (VI),

R⁶ and R⁷ each independently represent a hydrogen atom, a C₁₋₆ alkylgroup, which may be substituted by one or more halogen atoms, or a C₃₋₆cyclic alkyl group, which may be substituted by one or more halogenatoms, or R⁶ and R⁷ together represent an alkylene group to form afive-membered or six-membered ring,

R⁸ represents a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, or a C₇₋₁₂aralkyl group, or R⁶ and R⁸ together represent an alkylene group whichforms a five- or six-membered ring together with the interposing —C—O—group, the carbon atom in the ring being optionally substituted by anoxygen atom,

R⁹ represents a C₁₋₆ alkyl group or a C₃₋₆ cyclic alkyl group, one ortwo carbon atoms in the alkyl group or the cyclic alkyl group beingoptionally substituted by an oxygen atom, a C₆₋₁₂ aryl group, or a C₇₋₁₂aralkyl group,

R¹⁰ and R¹¹ each independently represent a hydrogen atom, a C₁₋₆ alkylgroup, or a C₃₋₆ cyclic alkyl group,

R¹² represents a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, a C₆₋₁₂aryl group, or a C₇₋₁₂ aralkyl group, and

R¹³ represents a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, aC₆₋₁₂aryl group, a C₇₋₁₂ aralkyl group, group —Si(R¹²)₂R¹³, or group—O—Si(R¹²)₂R¹³.

According to another preferred embodiment of the present invention, agroup of compounds represented by formula (I) are utilized wherein

R¹, R², R³, R⁴, and R⁵ each independently represent a C₁₋₃ alkyl group,a C₃₋₆ monocyclic alkyl group, C₁₀₋₁₂ bicyclic alkyl group, a C₃₋₆cyclic alkylcarbonyl group, a phenyl group, or a naphthyl group, or anytwo of R¹, R² and R³, or R⁴ and R⁵ together represent an alkylene groupto form a five- or six-membered alkylene ring,

one or more hydrogen atoms of R¹, R², R³, R⁴, and R⁵ optionallysubstituted by at least one group selected from the group consisting ofa hydrogen atom, a halogen atom, a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkylgroup, a C₁₋₆ alkoxyl group, a C₃₋₆ cyclic alkoxyl group, a hydroxylgroup, an aryl group, an aryloxy group, an arylthio group, and groups offormulae (II) to (VI) wherein R⁶ and R⁷ each independently representeither a hydrogen atom or a methyl group, provided that R⁶ and R⁷ do notsimultaneously represent hydrogen, Ra represents either a C₁₋₄ alkylgroup or R⁶ and R⁸ together represent an alkylene group which forms aring together with the interposing —C—O— group, R⁹ represents a C₁₋₄alkyl group, R¹⁰ and R¹¹ represent a hydrogen atom, R¹² represents amethyl group, and R¹³ represents a methyl group.

According to the present invention, the most preferred compoundsrepresented by formula (1) are tris-(4-t-butylphenyl)sulfonium3,3,3,2,1,1-hexafluorobutane sulfonate and tris-(4-t-butylphenyl)sulfonium nonafluorobutane sulfonate. These compounds can advantageouslyoffer excellent lithographic performance and, in addition, can be easilysynthesized.

Specific examples of preferred onium salts represented by formula (I)include, but are not limited to, the following compounds (in this list,sulfonium 3,3,3,2,1,1-hexafluorobutane sulfonate is abbreviated asS-HFPS and iodonium 3,3,2,1,1-hexafluorobutane sulfonate is abbreviatedas I-HFPS): triphenyl S-HFPS, 4-methylphenyl diphenyl S-HFPS,bis-(4-methylphenyl) phenyl S-HFPS, tris-(4-methylphenyl) S-HFPS,4-t-butylphenyl diphenyl S-HFPS, bis-(4-t-butylphenyl) phenyl S-HFPS,tris-(4-t-butylphenyl) S-HFPS, 4-cyclohexylphenyl diphenyl S-HFPS,bis-(4-cyclohexylphenyl) phenyl S-HFPS, tris-(4-cyclohexylphenyl)S-HFPS, 4-chlorophenyl diphenyl S-HFPS, bis-(4-chlorophenyl) phenylS-HFPS, tris-(4-chlorophenyl) S-HFPS, 4-N,N-dimethylaminophenyl diphenylS-HFPS, bis-(4-N,N-dimethylaminophenyl) phenyl S-HFPS,tris-(4-N,N-dimethylaminophenyl) S-HFPS, 4-hydroxyphenyl diphenylS-HFPS, bis-(4-hydroxyphenyl) phenyl S-HFPS, tris-(4-hydroxyphenyl)S-HFPS, 4-methoxyphenyl diphenyl S-HFPS, bis-(4-methoxyphenyl) phenylS-HFPS, tris-(4-methoxyphenyl) S-HFPS, 4-t-butyloxyphenyl diphenylS-HFPS, bis-(4-t-butyloxyphenyl) phenyl S-HFPS,tris-(4-t-butyloxyphenyl) S-HFPS, 3,5-dimethyl-4-hydroxyphenyl diphenylS-HFPS, bis-(3,5-dimethyl-4-hydroxyphenyl) phenyl S-HFPS,tris-(3,5-dimethyl-4-hydroxyphenyl) S-HFPS,4-t-butyloxycarbonyloxyphenyl diphenyl S-HFPS,bis-(4-t-butyloxycarbonyloxyphenyl) phenyl S-HFPS,tris-(4-t-butyloxycarbonyloxyphenyl) S-HFPS, 4-t-butyloxycarbonylphenyldiphenyl S-HFPS, bis-(4-t-butyloxycarbonylphenyl) phenyl S-HFPS,tris-(4-t-butyloxycarbonylphenyl) S-HFPS,4-t-butyloxycarbonylmethylenoxyphenyl diphenyl S-HFPS,bis-(4-t-butyloxycarbonylphenyl) phenyl S-HFPS,tris-(4-t-butyloxycarbonylphenyl) S-HFPS, 4-phenythiophenyl diphenylS-HFPS, bis-(4-phenylthiophenyl diphenyl) phenyl S-HFPS,tris-(4-phenylthiophenyl diphenyl) S-HFPS, 2-naphthyl diphenyl S-HFPS,phenyl anthrylium HFPS, phenyl thioanthrylium HFPS, 9-anthryl diphenylS-HFPS, 4 methylphenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-methylphenyl) 4-t-butylphenyl S-HFPS, 4-t-butyloxyphenylbis-(4-t-butylphenyl) S-HFPS, bis-(4-t-butyloxyphenyl) 4-t-butylphenylS-HFPS, 4-cyclohexylphenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-cyclohexylphenyl) 4-t-butylphenyl S-HFPS, 4-chlorophenylbis-(4-t-butylphenyl) S-HFPS, bis-(4-chlorophenyl) 4-t-butylphenylS-HFPS, 4-N,N-dimethylaminophenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-N,N-dimethylaminophenyl) 4-t -butylphenyl S-HFPS, 4-hydroxyphenylbis-(4-t-butylphenyl) S-HFPS, bis-(4-hydroxyphenyl) 4-t-butylphenylS-HFPS, 4-methoxyphenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-methoxyphenyl) 4-t-butylphenyl S-HFPS,3,5-dimethyl-4-hydroxyphenyl bis-(4-t-butylphenyl) S-HFPS,bis-(3,5-dimethyl-4-hydroxyphenyl) 4-t-butylphenyl S-HFPS,4-t-butyloxycarbonyloxyphenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-t-butyloxycarbonyl oxyphenyl) 4-t-butylphenyl S-HFPS,4-t-butyloxycarbonyl phenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-t-butyloxycarbonylphenyl) 4-t-butylphenyl S-HFPS,4-t-butyloxycarbonyl methylenoxyphenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-t-butyloxycarbonylmethylen oxyphenyl) 4-t-butylphenyl S-HFPS,4-phenylthiophenyl bis-(4-t-butylphenyl) S-HFPS,bis-(4-phenylthiophenyl) 4-t-butylphenyl S-HFPS, 2-naphthylbis-(4-t-butylphenyl) S-HFPS, 9-anthryl bis-(4-t-butylphenyl) S-HFPS,bis-(4-methylphenyl) 4-methoxyphenyl S-HFPS, 4-t-butylphenylbis-(4-methoxyphenyl) S-HFPS, bis-(4-t-butylphenyl) 4-methoxyphenylS-HFPS, 4-cyclohexylphenyl bis-(4-methoxyphenyl) S-HFPS,bis-(4-cyclohexylphenyl) 4-methoxyphenyl S-HFPS, 4-chlorophenylbis-(4-methoxyphenyl) S-HFPS, bis-(4-chlorophenyl) 4-methoxyphenylS-HFPS, 4-N,N-dimethylaminophenyl bis-(4-methoxyphenyl) S-HFPS,bis-(4-N,N-dimethylaminophenyl ) 4-methoxyphenyl S-HFPS ,4-hydroxyphenyl bis-(4-methoxyphenyl) S-HFPS, bis-(4-hydroxyphenyl)4-methoxyphenyl S-HFPS, 4-t-butyloxyphenyl bis-(4-methoxyphenyl) S-HFPS,bis-(4-t-butyloxyphenyl) 4-methoxyphenyl S-HFPS,3,5-dimethyl-4-hydroxyphenyl bis-(4-methoxyphenyl) S-HFPS,bis-(3,5-dimethyl-4-hydroxyphenyl) 4-methoxyphenyl S-HFPS,4-t-butyloxycarbonyl oxyphenyl bis-(4-methoxyphenyl) S-HFPS,bis-(4-t-butyloxy carbonyloxyphenyl) 4-methoxyphenyl S-HFPS,4-t-butyloxycarbonylphenyl bis-(4-methoxyphenyl) S-HFPS,bis-(4-t-butyloxycarbonylphenyl) 4-methoxyphenyl S-HFPS,4-t-butyloxycarbonyl methylenoxyphenyl bis-(4-methoxyphenyl ) S-HFPS,bis-(4-t-butyloxycarbonylmethylen oxyphenyl) 4-methoxyphenyl S-HFPS,4-phenylthiophenyl bis-(4-methoxyphenyl) S-HFPS,bis-(4-phenylthiophenyl) 4-methoxyphenyl S-HFPS, 2-naphthylbis-(4-methoxyphenyl) S-HFPS, 9-anthryl bis-(4-methoxyphenyl) S-HFPS,4-cyclohexylphenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(4-cyclohexylphenyl) 4-t-butyloxyphenyl S-HFPS, 4-chlorophenylbis-(4-t-butyloxyphenyl) S-HFPS, bis-(4-chlorophenyl) 4-t-butyloxyphenylS-HFPS, 4-N,N-dimethylaminophenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(4-N,N-dimethyl aminophenyl) 4-t-butyloxyphenyl S-HFPS,4-hydroxyphenyl bis-(4-t-butyloxyphenyl) S-HFPS, bis-(4-hydroxyphenyl)4-t-butyloxyphenyl S-HFPS, 4-methoxyphenyl bis-(4-t-butyloxyphenyl)S-HFPS, bis-(4-methoxyphenyl) 4-t-butyloxyphenyl S-HFPS,3,5-dimethyl-4-hydroxyphenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(3,5-dimethyl-4-hydroxyphenyl) 4-t-butyloxyphenyl S-HFPS,4-t-butyloxycarbonyloxyphenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(4-t-butyloxycarbonyloxyphenyl) 4-t-butyloxyphenyl S-HFPS,4-t-butyloxycarbonyl phenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(4-t-butyloxycarbonylphenyl) 4-t-butyloxy phenyl S-HFPS,4-t-butyloxycarbonylmethylenoxyphenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(4-t-butyloxycarbonylmethylenoxyphenyl) 4-t-butyloxyphenyl S-HFPS,4-phenyl thiophenyl bis-(4-t-butyloxyphenyl) S-HFPS,bis-(4-phenylthiophenyl) 4-t-butyloxy phenyl S-HFPS, 2-naphthylbis-(4--butyloxyphenyl) S-HFPS, 9-anthryl bis-(4-t-butyloxyphenyl)S-HFPS, trimethyl S-HFPS, butyl dimethyl S-HFPS, dibutyl methyl S-HFPS,cyclohexyl methyl S-HFPS, dicyclohexyl methyl S-HFPS, β-oxocyclohexyldimethyl S-HFPS, β-oxocyclohexyl cyclohexyl methyl S-HFPS,β-oxocyclohexyl 2-norbornyl methyl S-HFPS, phenyl dimethyl S-HFPS,diphenyl methyl S-HFPS, 4-methylphenyl dimethyl S-HFPS,bis-(4-methylphenyl) methyl S-HFPS, 4-t-butylphenyl dimethyl S-HFPS,bis-(4-t-butylphenyl) methyl S-HFPS, 4-t-butyloxyphenyl dimethyl S-HFPS,bis-(4-t-butyloxyphenyl) methyl S-HFPS, 4-cyclohexylphenyl dimethylS-HFPS, bis-(4-cyclohexylphenyl) methyl S-HFPS, 4-chlorophenyl dimethylS-HFPS, bis-(4-chlorophenyl) methyl S-HFPS, 4-N,N-dimethylaminophenyldimethyl S-HFPS, bis-(4-N,N-dimethylaminophenyl) methyl S-HFPS,4-hydroxyphenyl dimethyl S-HFPS, bis-(4-hydroxyphenyl) methyl S-HFPS,3,5-dimethyl-4-hydroxyphenyl dimethyl S-HFPS,bis-(3,5-dimethyl-4-hydroxyphenyl) methyl S-HFPS,3,5-dimethoxy-4-hydroxyphenyl dimethyl S-HFPS,bis-(3,5-dimethoxy-4-hydroxyphenyl) methyl S-HFPS, 4-methoxyphenyldimethyl S-HFPS, bis-(4-methoxyphenyl) methyl S-HFPS,4-t-butyloxycarbonyloxyphenyl dimethyl S-HFPS,bis-(4-t-butyloxycarbonyloxyphenyl) methyl S-HFPS,4-t-butyloxycarbonylphenyl dimethyl S-HFPS,bis-(4-t-butyloxycarbonylphenyl) methyl S-HFPS,4-t-butyloxycarbonylmethylenoxyphenyl dimethyl S-HFPS,bis-(4-t-butyloxycarbonylmethylenoxyphenyl) methyl S-HFPS,4-phenylthiophenyl dimethyl S-HFPS, bis-(4-phenylthiophenyl) methylS-HFPS, 2-naphthyl dimethyl S-HFPS, bis-(2-naphthyl) methyl S-HFPS,4-hydroxynaphthyl dimethyl S-HFPS, bis-(4-hydroxynaphthyl) methylS-HFPS, 9-anthryl dimethyl S-HFPS, bis-(9-anthryl) methyl S-HFPS,2-naphthyl dibutyl S-HFPS, phenyl tetramethylene S-HFPS, 4-methylphenyltetramethylene S-HFPS, 4-t-butylphenyl tetramethylene S-HFPS,4-t-butyloxyphenyl tetramethylene S-HFPS, 4-cyclohexylphenyltetramethylene S-HFPS, 4-chlorophenyl tetramethylene S-HFPS,4-N,N-dimethylaminophenyl tetramethylene S-HFPS, 4-hydroxyphenyltetramethylene S-HFPS, 3,5-dimethyl-4-hydroxyphenyl tetramethyleneS-HFPS, 3,5-dimethoxy-4-hydroxyphenyl tetramethylene S-HFPS,4-methoxyphenyl tetramethylene S-HFPS, 4-t-butyloxycarbonyloxyphenyltetramethylene S-HFPS, 4-t-butyloxycarbonylphenyl tetramethylene S-HFPS,4-t-butyloxycarbonylmethylenoxyphenyl tetramethylene S-HFPS,4-phenylthiophenyl tetramethylene S-HFPS, 2-naphthyl tetramethyleneS-HFPS, 4-hydroxynaphthyl tetramethylene S-HFPS, 9-anthryltetramethylene S-HFPS, phenyl pentamethylene S-HFPS, 4-methylphenylpentamethylene S-HFPS, 4-t-butylphenyl pentamethylene S-HFPS,4-t-butyloxyphenyl pentamethylene S-HFPS, 4-cyclohexylphenylpentamethylene S-HFPS, 4-chlorophenyl pentamethylene S-HFPS,4-N,N-dimethylaminophenyl pentamethylene S-HFPS, 4-hydroxyphenylpentamethylene S-HFPS, 3,5-dimethyl-4-hydroxyphenyl pentamethyleneS-HFPS, 3,5-dimethoxy-4-hydroxyphenyl pentamethylene S-HFPS,4-methoxyphenyl pentamethylene S-HFPS, 4-t-butyloxycarbonyloxyphenylpentamethylene S-HFPS, 4-t-butyloxycarbonylphenyl pentamethylene S-HFPS,4-t-butyloxycarbonyl methylenoxyphenyl pentamethylene S-HFPS,4-phenylthiophenyl pentamethylene S-HFPS, 2-naphthyl pentamethyleneS-HFPS, 4-hydroxynaphthyl pentamethylene S-HFPS, 9-anthrylpentamethylene S-HFPS, phenylcarbonylmethylene dimethyl S-HFPS,phenylcarbonylmethylene tetramethylene S-HFPS, phenylcarbonylmethylenepentamethylene S-HFPS, 2-naphthylcarbonylmethylene dimethyl S-HFPS,2-naphthylcarbonylmethylene tetramethylene S-HFPS,2-napthylcarbonylmethylene pentamethylene S-HFPS, diphenyl I-HFPS,bis-(4-methylphenyl) I-HFPS, bis-(3,4-dimethylphenyl) I-HFPS,bis-(4-t-butylphenyl) I-HFPS, bis-(4-t-butyloxyphenyl) I-HFPS,bis-(4-cyclohexylphenyl) I-HFPS, bis-(4-trifluoromethylphenyl) I-HFPS,bis-(4-chlorophenyl) I-HFPS, bis-(2,4-dichlorophenyl) I-HFPS,bis-(4-dimethylaminophenyl) I-HFPS, bis-(4-hydroxyphenyl) I-HFPS,bis-(3,5-dimethyl-4-hydroxyphenyl) I-HFPS, bis-(4-methoxyphenyl) I-HFPS,bis-(4-t-butyloxycarbonyloxyphenyl) I-HFPS,bis-(4-t-butyloxycarbonylphenyl) I-HFPS, bis-(4-t-butyloxycarbonylmethylene oxyphenyl) I-HFPS, bis-(4-phenylthiophenyl) I-HFPS,bis-(3-methoxycarbonylphenyl) I-HFPS, bis-(2-naphthyl) I-HFPS, dithienylthienyl 1-HFPS, 4-methylphenyl phenyl I-HFPS, 3,4-dimethylphenyl phenylI-HFPS, 4-t-butylphenyl phenyl I-HFPS, 4-t-butyloxyphenyl phenyl I-HFPS,4-cyclohexylphenyl phenyl I-HFPS, 4-trifluoromethylphenyl phenyl I-HFPS,4-chlorophenyl phenyl I-HFPS, 2,4-dichlorophenyl phenyl I-HFPS,4-dimethylaminophenyl phenyl I-HFPS, 4-hydroxyphenyl phenyl I-HFPS,3,5-dimethyl-4-hydroxyphenyl phenyl I-HFPS, 4-methoxyphenyl phenylI-HFPS, 4-t-butyloxycarbonyloxyphenyl phenyl I-HFPS,4-t-butyloxycarbonylphenyl phenyl I-HFPS, 4-t-butyloxocarbonylmethyleneoxyphenyl phenyl I-HFPS, 4-phenylthiophenyl phenyl I-HFPS,3-methoxycarbonylphenyl phenyl I-HFPS, 2-naphthyl phenyl I-HFPS,9-anthryl phenyl I-HFPS, thienyl phenyl I-HFPS, and onium salts whereinS-HFPS of the above compounds have been replaced with sulfoniumnonafluorobutane sulfonate, and onium salts wherein I-HFPS of the abovecompounds have been replaced with iodonium fluorobutane sulfonate.

The onium salt precursor, which generates a fluorinated alkanesulfonicacid, may be synthesized by various processes. For example, thesulfonium salt may be synthesized by a process described in Y. Endo, K.Shudo, and T. Okamato, Chem. Pharm Bull., 29, 3753-3755 (1981), and bythe same process described in a synthesis example described in J. V.Crivello and J. H. W. Lam, Macromolecules, 10, 1307-1315 (1977).

The onium salt precursors, which generate fluorinated alkanesulfonicacids, may be contained alone or as a mixture of two or more in thecomposition according to the present invention.

According to the composition of the present invention, the amount of theonium salt precursor added, which generates a fluorinated alkanesulfonicacid, may be properly determined in such an amount range as will providethe effect of the onium salt pecursor. In the case of thepositive-working chemically amplified radiation sensitive composition,the amount of the onium salt precursor added is preferably about 0.1 to30 parts by weight, more preferably about 0.5 to 15 parts by weight,based on 100 parts by weight of the film forming hydroxystyrene basedresin present in the composition. On the other hand, in the case of thenegative-working chemically amplified radiation sensitive composition,the amount of the onium salt precursor added is preferably about 0.1 to30 parts by weight, more preferably about 0.5 to 15 parts by weight,based on 100 parts by weight of the film forming hydroxystyrene basedresin present in the composition.

If required, the onium salts precursor of the present invention, whichgenerate fluorinated alkanesulfonic acids, may be used in combinationwith other PAGs. Preferable PAGs are those which can maintain hightransparency of the (a) positive-working or (b) negative-workingchemically amplified radiation sensitive composition at the irradiationwavelength, particularly near 365 nm, 248 nm, or 193 nm. As a generalfeature, suitable additional PAGs should produce acids, preferablysulfonic acids, which have a boiling point above 150° C. Examples ofpreferred PAGs include various anionic sulfonium salts or iodoniumsalts. Examples thereof include sulfonium or iodonium camphorsulfonates, sulfonium or iodonium 2,4-dimethylbenzenesulfonates,sulfonium or iodonium toluenesulfonates, sulfonium or iodoniumpentafluorobenzenesulfonates, 1-anthrylsulfonates, or9,10-dimethoxyanthrylsulfonates. Especially preferred are the sulfoniumor iodonium 2-acrylamido-2-methyl-1-propanesulfonates. Other examples ofpreferred ionic PAGs include the respective diazonium salts, ammoniumsalts, phosphonium salts, selenonium salts, or arsonium salts. Examplesof preferred nonionic PAGs include o-nitrobenzyl sulfonates, arylsulfonates,bis-[(2,2,2-trifluoro-1-alkylsulfonyloxy)-1-trifluoromethylethyl]-benzenes,bis-[(2,2,2-trifluoro-1-arylsulfonyloxy)-1-trifluoromethylethyl]-benzenes,α, α-bis-(arylsulfonyl)diazomethanes, α,α-bis-(alkylsulfonyl)diazomethanes, α, α-bis-(arylsulfonyl)methanes,diarylsulfones, α-arylcarbonyl-α-arylsulfonyldiazomethanes,α-arylcarbonyl-α-arylsulfonylmethanes, α-hydroxymethyl benzoinsulfonates, oximesulfonates, iminosulfonates, and N-sulfonyloxypyridones. Especially preferred is the combination of the onium salts ofthe present invention with α, α-bis-(arylsulfonyl)diazomethanes or α,α-bis-(alkylsulfonyl)diazomethanes as non-ionic PAGs.

(b) Film Forming Hydroxystyrene Based Resin

The composition according to the present invention comprises a filmforming hydroxystyrene based resin. The film forming hydroxystyrenebased resin refers to a polymer of 4-hydroxystyrene, 3-hydroxystyrene,or 2-hydroxystryene, or a co-, ter-, quater- or pentapolymer of thestyrenes and other monomers. As described below, different modificationsor properties are required of the film forming hydroxystyrene basedresin depending upon whether the chemically amplified radiationsensitive composition is of positive-working type or negative-workingtype.

(i) Where Chemically Amplified Radiation Sensitive Composition is ofPositive-working Type

When the chemically amplified radiation sensitive composition of thepresent invention is of positive-working type, the film forminghydroxystyrene based resin is made alkali insoluble by protecting alkalisoluble groups on the resin with an acid cleavable protective group.According to a preferred embodiment of the present invention, thehydroxystyrene based resin has multiple acid cleavable (preferablypendant) C—O—C or C—O—Si groups and is made alkali insoluble byprotecting alkali soluble groups on the resin by the acid cleavableprotective groups.

According to a preferred embodiment of the present invention, thehydroxystyrene based resin has a molecular weight in the range of 2,000to about 100,000 with the polydispersity being in the range of 1.01 to2.99, more preferably a molecular weight in the range of 2,000 to 20,000with the polydispersity being not more than 2.20.

According to a preferred embodiment of the present invention, thetransmission per micrometer film thickness of the hydroxystyrene basedresin is generally better than 50% at irradiation wave length. Thesolubility of the base resin, not protected by acid cleavable groups, ina standard aqueous alkaline developer solution (2.38%tetramethylammonium hydroxide) at 21° C. is preferably above 5,000angstrom/min, more preferably above 10,000 angstrom/min. On the otherhand, the hydroxystyrene based resin protected by acid cleavable groupshas virtually no solubility. That is, the solubility thereof in the samestandard aqueous alkaline developer solution is preferably less than 800angstrom/min, more preferably less than 400 angstrom/min.

According to the composition of the present invention, the base skeletonof the hydroxystyrene based resin is not particularly limited and may beproperly determined by taking into consideration applications of thecomposition, radiation wavelength for exposure, production conditions,chemical composition and the like. According to a preferred embodimentof the present invention, examples of hydroxystyrene based resins usableherein include: poly-(4-hydroxystyrene); poly-(3-hydroxystyrene);poly-(2-hydroxystyrene); and copolymers of 4-, 3-, or 2-hydroxystyrenewith other monomers, particularly bipolymers and terpolymers. Examplesof other monomers usable herein include 4-, 3-, or 2-acetoxystyrene, 4-,3-, or 2-alkoxystyrene, styrene, α-methylstyrene, 4-, 3-, or2-alkylstyrene, 3-alkyl-4-hydroxystyrene, 3,5-dialkyl-4-hydroxystyrene,4-, 3-, or 2-chlorostyrene, 3-chloro-4-hydroxystyrene,3,5-dichloro-4-hydroxystyrene, 3-bromo-4-hydroxystyrene,3,5-dibromo-4-hydroxystyrene, vinylbenzyl chloride, 2-vinylnaphthalene,vinylanthracene, vinylanilline, vinylbenzoic acid, vinylbenzoic acidesters, N-vinylpyrrolidone, 1-vinylimidazole, 4-, or 2-vinylpyridine,1-vinyl-2-pyrrolidinone, N-vinyl lactam, 9-vinylcarbazole, vinylbenzoate, acrylic acid and its derivatives, i.e. methyl acrylate and itsderivatives, acrylamide and its derivatives, methacrylic acid and itsderivatives, i.e. methyl methacrylate and its derivatives,methacrylamide and its derivatives, acrylonitrile, methacrylonitrile,4-vinyl benzoic acid and its derivatives, i.e. 4-vinyl benzoic acidesters, 4-vinylphenoxy acetic acid and its derivatives, i.e.4-vinylphenoxy acetic acid esters, maleimide and its derivatives,N-hydroxymaleimide and its derivatives, maleic anhydride, maleic/fumaricacid and their derivatives, i.e. maleic/fumaric acid ester,vinyltrimethylsilane, vinyltrimethoxysilane, or vinyl-norbornene and itsderivatives. Another examples of preferred other monomers usable hereininclude isopropenylphenol, propenylphenol, poly-(4-hydroxyphenyl)(meth)acrylate, poly-(3-hydroxyphenyl) (meth)acrylate,poly-(2-hydroxyphenyl) (meth)acrylate, N-(4-hydroxyphenyl)(meth)acrylamide, N-(3-hydroxyphenyl) (meth)acrylamide,N-(2-hydroxyphenyl) (meth)acrylamide, N-(4-hydroxybenzyl)(meth)acrylamide, N-(3-hydroxybenzyl) (meth)acrylamide,N-(2-hydroxybenzyl) (meth)acrylamide,3-(2-hydroxy-hexafluoropropyl-2)-styrene, and4-(2-hydroxy-hexafluoropropyl-2)-styrene.

As described above, when the chemically amplified radiation sensitivecomposition is of positive-working type, the hydroxystyrene based resinis made alkali insoluble by protecting alkali soluble groups on theresin with an acid cleavable protective group. The introduction of theprotective group may be carried out by an proper method depending uponalkali soluble groups on the resin, and could be easily carried out by aperson having ordinary skill in the art.

For example, when the alkali soluble group on the resin is a phenolichydroxyl group, the phenolic hydroxyl groups present in the resin arepartly or fully protected by an acid labile protective group, preferablyby one or more protective groups which form acid cleavable C—O—C orC—O—Si bonds. Examples of protective groups usable herein include acetalor ketal groups formed from alkyl or cycloalkyl vinyl ethers, silylethers formed from suitable trimethylsilyl or t-butyl(dimethyl)silylprecursors, alkyl ethers formed from methoxymethyl, methoxyethoxymethyl,cyclopropylmethyl, cyclohexyl, t-butyl, amyl, 4-methoxybenzyl,o-nitrobenzyl, or 9-anthrylmethyl precursors, t-butyl carbonates formedfrom t-butoxycarbonyl precursors, and carboxylates formed from t-butylacetate precursors.

When the alkali soluble group on the resin is a carboxyl group, thecarboxyl groups present on the resin are partly or fully protected by anacid labile protective group, preferably by one or more protectivegroups which form acid cleavable C—O—C or C—O—Si bonds. Examples ofprotective groups usable herein include alkyl or cycloalkyl vinyl ethersand esters formed from precursors containing methyl, methyloxymethyl,methoxyethoxymethyl, benzyloxymethyl, phenacyl, N-phthalimidomethyl,methylthiomethyl, t-butyl, amyl, cyclopentyl, 1-methylcyclopentyl,cyclohexyl, 1-methylcyclohexyl, 2-oxocyclohexyl, mevalonyl,diphenylmethyl, α-methylbenzyl, o-nitrobenzyl, p-methoxybenzyl,2,6-dimethoxybenzyl, piperonyl, anthrylmethyl, triphenylmethyl,2-methyladamantyl, tetrahydropyranyl, tetrahydrofuranyl,2-alkyl-1,3-oxazolinyl, dibenzosuberyl, trimethylsilyl, ort-butyldimethylsilyl group.

According to the present invention, the above resins may be used aloneor as a mixture of two or more.

The hydroxystyrene based resin is especially useful for exposure withi-line (365 nm) or DUV (248 nm) radiation, e-beam, ion beam or x-rays.

According to a preferred embodiment of the present invention, some ofthe PAGs (photoacid generators) described above are especially suitablefor exposure with VDUV (193 nm) radiation, as they exhibit excellentabsorption characteristics at this specific wavelength.

Examples of hydroxystyrene based resins suitable for VDUV (193 nm)applications include co- or terpolymers of (meth)acrylates withacid-cleavable protective groups and methyl (meth)acrylate, isobornyl(meth)acrylate, adamantyl (meth)acrylate, norbornyl (meth)acrylate,tricyclo[5.2.1.0.^(2.6)]decanyl (meth)acrylate, or menthyl(meth)acrylate, co- or terpolymers of maleic acid anhydride withnorbornene, 5,6-dihydrodicyclopentadiene, or 1,5-cyclooctadienederivatives as disclosed in EP 794,458A1, or copolymers withpolyalkylcyclic compounds, such as 8-methyl-8-carboxytetracyclo[4.4.0.1.^(2.5).1.^(7.10)]dodecene, 8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1.^(2.5).1.^(7.10)] dodecene,5-methyl-5-methoxycarbonyl bicyclo[2.2.1] hept-2-ene, or8,9-dicarboxylic anhydride tetracyclo [4.4.0.1.^(2.5).1.^(7.10)]dodec-3-ene as disclosed in EP 789,278A2 and WO 97/33,198.

According to a preferred embodiment of the present invention, when thepositive-working radiation sensitive composition according to thepresent invention may contain a dissolution inhibitor. According to thepresent invention, the dissolution inhibitor per se is not an essentialcomponent of the composition which creates good lithographicperformance. However, the dissolution inhibitor is often useful forimproving specific properties of the positive-working radiationsensitive composition.

Examples of preferred dissolution inhibitors usable herein includepolymer, oligomer, or monomer compounds having at least one acidcleavable C—O—C or C—O—Si groups. According to the present invention,oligomers or low-molecular weight compounds having a molecular weight ofnot more than 3,500, particularly not more than 1,000, are preferred.More specific examples of dissolution inhibitors usable herein includemonomer or oligomer compounds having 1 to 10 phenolic hydroxyl groupswhich are partly or fully protected by a protective group having acidcleavable C—O—C or C—O—Si bonds. Protective groups, which provide suchbonds, include acetal or ketal formed from aliphatic or alicyclic vinylether, silyl ethers formed from suitable trimethylsilyl ort-butyl(dimethyl)silyl precursors, alkyl ethers formed frommethoxymethyl, methoxyethoxymethyl, cyclopropylmethyl, cyclohexyl,t-butyl, amyl, 4-methoxybenzyl, o-nitrobenzyl, or 9-anthrylmethylprecursors, t-butyl carbonates formed from t-butoxycarbonyl precursors,and t-butyl or related phenoxyacetates formed from t-butyl or relatedacetate precursors. Further specific examples of dissolution inhibitorsusable herein include monomer or oligomer compounds having 1 to 6carboxyl groups which are partly or fully protected by a protectivegroup having an acid cleavable C—O—C or C—O—Si bonds. Protective groups,which provide such bonds, include aliphatic or cycloaliphatic vinylethers and esters formed from precursors containing methyl,methyloxymethyl, methoxyethoxymethyl, benzyloxymethyl, phenacyl,N-phthalimidomethyl, methylthiomethyl, t-butyl, amyl, cyclopentyl,1-methylcyclopentyl, cyclohexyl, 1-methylcyclohexyl, 2-oxocyclohexyl,mevalonyl, diphenylmethyl, α-methylbenzyl, o-nitrobenzyl,p-methoxybenzyl, 2,6-dimethylbenzyl, piperonyl, anthrylmethyl,triphenylmethyl, 2-methyladamantyl, tetrahydropyranyl,tetrahydrofuranyl, 2-alkyl-1,3-oxazolinyl, dibenzosuberyl,trimethylsilyl, or t-butyldimethylsilyl group.

Further examples of preferred dissolution inhibitors include thefollowing compounds:

1. those having at least one orthocarboxylate ororthocarboxyamide-acetal groups, with the option to be polymeric innature and for the said groups to appear as linking elements in the mainchain or as side-chain substituents (DE 2,3610,842 and DE 2,928,636);

2. oligomeric or polymeric compounds having recurring acetal or ketalgroups in the main chain (DE 2,306,248 and DE 2,718,254);

3. compounds having at least one enol ether or N-acyliminocarbonategroup (EP 0,006,626 and 0,006,627);

4. cyclic acetals or ketals of b-ketoesters or -amides (EP 0,202,196);

5. compounds having silyl ether groups (DE 3,544,165 and DE 3,601,264);

6. compounds having silyl enol ether groups (DE 3,730,785 and DE3,730,783);

7. monoacetals or monoketals whose aldehyde or keto component has asolubility in the developer between 0.1 and 100 g/l (DE 3,730,787);

8. oligomer or polymer N,O-acetals (U.S. Pat No. 5,286,602);

9. monomer or polymer acetals with t-butyloxycarbonyl groups (U.S. Pat.No. 5,356,752 and U.S. Pat. No. 5,354,643); and

10. monomer or polymer acetals with sulfonyloxy groups (U.S. Pat. No.5,346,804 and U.S. Pat. No. 5,346,806).

These dissolution inhibitors may be added alone or as a mixture of twoor more to the composition.

(ii) Where Chemically Amplified Radiation Sensitive Composition is ofNegative-working Type

When the radiation sensitive composition of the present invention is ofpositive-working type, the composition comprises an photoacid generator,a film forming alkali soluble hydroxystyrene based resin, and, inaddition, optionally an acid-sensitive crosslinking agent. Specifically,when the resin is an acid-sensitive self-crosslinkable resin, thecrosslinking agent is unnecessary. On the other hand, when the resin isnot self-crosslinkable, the composition according to the presentinvention further comprises an acid-sensitive crosslinking agent.

According to a preferred embodiment of the present invention, in thenegative-working radiation sensitive composition, the hydroxystyrenebased resin has a molecular weight in the range of 2,000 to about100,000 with the polydispersity being in the range of 1.01 to 2.80, morepreferably a molecular weight in the range of 2,000 to 20,000 with thepolydispersity being not more than 2.20.

According to a preferred embodiment of the present invention, thetransmission per micrometer film thickness of the hydroxystyrene basedresin is better than 50% for light at irradiation wavelength. Thesolubility of the resin in a water-soluble standard alkaline developersolution (2.38% tetramethylammonium hydroxide) at 21° C. is preferablyabove 1,000 angstrom/min, more preferably above 3,000 angstrom/min.According to the composition of the present invention, the base skeletonof the hydroxystyrene based resin is not particularly limited and may beproperly determined by taking into consideration applications of thecomposition, radiation wavelength for exposure, production conditions,chemical composition and the like. According to a preferred embodimentof the present invention, examples of hydroxystyrene based resins usableherein include: poly-(4-hydroxystyrene); poly-(3-hydroxystyrene);poly-(2-hydroxystyrene); and copolymers of 4-, 3-, or 2-hydroxystyrenewith other monomers, particularly bipolymers and terpolymers. Examplesof other monomers usable herein include 4-, 3-, or 2-acetoxystyrene, 4-,3-, or 2-alkoxystyrene, styrene, α-methylstyrene, 4-, 3-, or2-alkylstyrene, 3-alkyl-4-hydroxystyrene, 3,5-dialkyl-4-hydroxystyrene,4-, 3-, or 2-chlorostyrene, 3-chloro-4-hydroxystyrene,3,5-dichloro-4-hydroxystyrene, 3-bromo-4-hydroxystyrene,3,5-dibromo-4-hydroxystyrene, vinylbenzyl chloride, 2-vinylnaphthalene,vinylanthracene, vinylanilline, vinylbenzoic acid, vinylbenzoic acidesters, N-vinylpyrrolidone, 1-vinylimidazole, 4-, or 2-vinylpyridine,1-vinyl-2-pyrrolidinone, N-vinyl lactam, 9-vinylcarbazole,vinylbenzoate, acrylic acid and its derivatives, i.e. methyl acrylateand its derivatives, glycidyl acrylate, acrylamide and its derivatives,methacrylic acid and its derivatives, i.e. methyl methacrylate and itsderivatives, glycidyl methacrylate, capped 2-isocyanate ethylmethacrylate, methacrylamide and its derivatives, acrylonitrile,methacrylonitrile, 4-vinyl benzoic acid and its derivatives, i.e.4-vinyl benzoic acid esters, 4-vinylphenoxy acetic acid and itsderivatives, i.e. 4-vinylphenoxy acetic acid esters, maleimide and itsderivatives, N-hydroxymaleimide and its derivatives, maleic anhydride,maleic acid and fumaric acid and their derivatives, i.e. maleic acidesters and fumaric acid esters, vinyltrimethylsilane,vinyltrimethoxysilane, or vinyl-norbornene and its derivatives. Anotherexamples of preferred other monomers usable herein includeisopropenylphenol, propenylphenol, poly-(4-hydroxyphenyl)(meth)acrylate, poly-(3-hydroxyphenyl) (meth)acrylate,poly-(2-hydroxyphenyl) (meth)acrylate, N-(4-hydroxyphenyl)(meth)acrylamide, N-(3-hydroxyphenyl) (meth)acrylamide,N-(2-hydroxyphenyl) (meth)acrylamide, N-(4-hydroxybenzyl)(meth)acrylamide, N-(3-hydroxybenzyl) (meth)acrylamide,N-(2-hydroxybenzyl) (meth)acrylamide,3-(2-hydroxy-hexafluoropropyl-2)-styrene, and4-(2-hydroxy-hexafluoropropyl-2)-styrene.

According to the chemically amplified radiation sensitive composition ofthe present invention, the resin is either acid-sensitiveself-crosslinkable or non-self-crosslinkable. In the former, at leastone acid-sensitive functional group is present in the resin. This acidsensitive group crosslinks the film forming alkali solublehydroxystyrene based resin molecule through an acid generated from thephotoacid generator to render the resin alkali insoluble. On the otherhand, the latter requires the presence of a crosslinking agent. Thiscrosslinking agent crosslinks the film forming alkali solublehydroxystyrene based resin through an acid generated from the photoacidgenerator to render the resin alkali insoluble. According to the presentinvention, the film forming hydroxystyrene based resin per se is notself-crosslinkable. However, at least one crosslinking portion of thecrosslinking agent may be introduced into the resin to render the resinself-crosslinkable.

According to a preferred embodiment of the present invention, examplesof crosslinking agents usable herein include oligomers or monomershaving at least two crosslinking portions. Various crosslinking agentsof this type are known in the art, and the crosslinking agent may beproperly selected by taking various conditions into consideration.Preferably, however, the crosslinking agent is selected based onradiation wavelength for exposure. For example, resols are not veryuseful crosslinkers for DUV irradiation due to their high inherentabsorption at this wavelength, but they may be employed whenconventional NUV illumination systems are used.

Examples of preferred crosslinking agents usable herein includemonomeric and oligomeric melamines/formaldehyde and urea/formaldehydecondensates as described in EP-A 133,216, DE-A 36 34 371 and DE 37 11264. More preferred crosslinking agents are urea/formaldehydederivatives which contain two to four N-hydroxymethyl, N-alkoxymethyl,or N-acyloxymethyl groups. In particular, the N-alkoxymethyl derivativesare suitable for use in the negative-working chemically amplifiedradiation sensitive composition of the present invention. Ureaderivatives with four N-alkoxymethyl groups are especially preferredbecause they provide better shelf life stability of the chemicallyamplified negative-working radiation sensitive composition thanderivatives with a smaller number of alkoxymethyl groups. The nature ofthe alkyl group in these derivatives is not particularly critical inthis connection, however, methoxymethyl groups are preferred. Theurea/formaldehyde compound may contain in addition to the methoxymethylgroups ethoxymethyl, propoxymethyl, or butoxymethyl groups or mixturesthereof. Also preferred are urea/formaldehyde derivatives which containtwo to six N-hydroxymethyl, N-alkoxymethyl, or N-acyloxymethyl groups.Melamine derivatives which contain on average at least three, inparticular at least 3.5 alkoxymethyl groups are preferred because theyprovide better shelf life stability of the negative-working chemicallyamplified radiation sensitive composition than derivatives with asmaller number of hydroxymethyl groups. The nature of the alkyl group inthese derivatives is not particularly critical in this connection,however, methoxymethyl groups are preferred. The melamine/formaldehydecompound may contain, in addition to the methoxymethyl groups,ethoxymethyl, propoxymethyl, or butoxymethyl groups or mixtures thereof.Mixtures of urea/formaldehyde compound and melamine/formaldehydecompound are particularly preferred. Before their use as crosslinkingagents in negative-working chemically amplified radiation sensitivecompositions, the above condensation products should be purified byrecrystallization or distillation and any water present should beremoved because traces of water have a negative impact on the shelf lifestability of the negative-working chemically amplified radiationsensitive composition. Various melamine and urea resins are commerciallyavailable. Here reference is made to the products Cymel® (Mitsui Cytec),Nicalacs® (Sanwa Chemical Co.), Plastopal® (BASF AG), or Maprenal®(Clariant GmbH).

Other suitable crosslinking agents are the resols disclosed in GB2,082,339. Commercially available products include Bakelite® R, orKelrez®. Also useful are the crosslinking agents disclosed in EP 212482, such as aromatic hydrocarbons containing two or three alkoxymethyl,hydroxymethyl or acyloxymethyl groups. Other crosslinking materialsinclude di- or trifunctional carbonyl aldehydes and ketones, acetals,enolethers, vinylethers, vinylesters, acrylates, methacrylates,epoxides, or divinylstyrene.

When the crosslinking agents is introduced into the resin to render theresin self-crosslinkable, examples of crosslinking agents usable forthis purpose include copolymers with (meth)acrylmethoxymethylamide,(meth)acrylvinyl-, -alkenyl-, -allyl-, or alkynyl esters, glycidyl(meth)acrylate or reaction products of 2-isocyanatoethyl methacrylatewith unsaturated alcohols or amines.

(c) Other Additives

Both the positive-working chemically amplified radiation sensitivecomposition and the negative-working chemical amplified radiationsensitive composition according to the present invention may furthercontain other performance improving additives such as dyes to adjust thematerial absorption, plasticizers to reduce the brittleness of thematerial film and to optimize the adhesion on the substrate, surfactantsto improve the material film uniformity, sensitizers to amplify thequantum yield of the PAG, photospeed enhancers to increase thephotosensitivity, solubility modulators to improve the contrast, thermalradical generators to improve the film hardness upon a hardbake, andbasic or acidic latent image stabilizers to improve the materialstability during its processing. Suitable dyes include e.g. aromaticdiazoketone derivatives, such as 9-diazo-10-phenanthrone,1-diazo-2-tetralone, o-napthoquinone diazido-4-sulfonic acid esters, oro-naphthoquinone diazido-5-sulfonic esters, benzophenone dervatives,such as 2,3,4-trihydroxy benzophenone, or 2,2′,4,4′-tetrahydroxybenzophenone, naphthalene, anthracene or phenanthrene derivatives, suchas 9-(2-methoxyethoxy)methylanthracene.

Suitable plasticizers include e.g. terephthalic acid esters, such asdioctyl terephthalate, or poly glycols, such as polyethylene glycol.

Suitable surfactants include nonionic surfactants, such as polyglycolsand their derivatives, i.e. polypropylene glycol, or polyoxyethylenelaurylether, fluorine containing surfactants, such as Fluorad™(available from Sumitomo 3M, Ltd.), Megafac ™ (available from DainipponInk & Chemicals, Inc.), Surflon™ (available from Asaki Glass Co., Ltd.),or organosiloxane surfactants, such as KP341 (available from ShinEtsuChemical Co., Ltd.).

Suitable sensitizers include e.g. thioxanthone, coumarin, orphenanthrene derivatives.

Photospeed enhancers include e.g. polyphenol or benzotriazolederivatives, such as resorcinol, catechol, or bisphenol A.

Solubility modulators include difunctional vinyl ethers, such as2,2′-bis(vinyloxyethoxyphenyl)propane ortris(vinyloxyethoxyphenyl)ethane, difunctional (meth)acrylates, such asethylene glycol di(meth)acrylate.

Thermal radical generators include peroxides, such as t-butylperbenzoate, or dicumyl peroxide, or azo-compounds having a scorchtemperature above 100° C.

Basic latent image stabilizers include amines, such as tribenzylamine,dicyclohexylamine, or triethanolamine, nitrogen containing heterocycles,such as lutidine, dimethylaminopyridine, pyrimidine, ammonium compounds,such as tetramethyl ammonium hydroxide, tetrabutyl ammonium hydroxide ortetramethyl ammonium lactate, or nitrogen containing polymers, such aspolyvinylpyridine, or polyvinylpyridine-co-methylmethacrylate.

Of special interest as latent image stabilizers are sulfoniumderivatives, such as triphenyl sulfonium hydroxide, triphenyl sulfoniumacetate, or triphenyl sulfonium lactate. Acidic latent image stabilizersinclude e.g. salicylic acid, Sax ™ (polysalicylic acid derivativesavailable from Mitsui Chemical K.K.), 4-dimethylamino benzoic acid orascorbic acid. Although the amount of these additives added may beappropriately determined, it is preferably about 0.0001 to 10 parts byweight based on unit weight of the chemically amplified radiationsensitive composition. According to the most preferred embodiment of thepresent invention, the positive-working chemically amplified radiationsensitive composition comprises

(1) 0.1 to 30 parts by weight of the sulfonium or iodonium salt of afluorinated alkanesulfonic acid represented by formula (I),

(2) 100 parts by weight of the film forming hydroxystyrene based resinhaving multiple acid cleavable C—O—C or C—O—Si bonds,

(3) 0 to 50 parts by weight of the dissolution inhibitor having at leastone acid cleavable C—O—C or C—O—Si bond; and

(4) 0.01 to 5.0 parts by weight of the performance improving additive.

Further, the negative-working chemically amplified radiation sensitivecomposition comprises

(1) 0.1 to 30 parts by weight of the sulfonium or iodonium salt of afluorinated alkanesulfonic acid represented by formula (I).

(2) 100 parts by weight of the hydroxystyrene based resin,

(3) 3 to 70 parts by weight of the acid-sensitive crosslinking agent,and

(4) 0.01 to 5.0 parts by weight of the performance improving additive.

Use of the Composition of the Present Invention/radiation SensitiveRecording Medium and Production Process Thereof

The chemically amplified radiation sensitive composition according tothe present invention is used as the so-called “photoresist” inapplications where the composition is coated on various substrates, andthe coated substrates are exposed to render latent images alkali solubleor alkali insoluble, followed by rinsing with an alkali to formpredetermined patterns on the substrates.

Thus, according to one aspect of the present invention, there isprovided a radiation sensitive recording medium comprising: a substrate;and a radiation sensitive layer provided on the substrate, the radiationsensitive layer comprising the composition according to the presentinvention.

The composition according to the present invention may be coated, eitheras such or after dissolution in various solvents, onto the substrate.Examples of preferred solvents include ethylene glycol and propyleneglycol and the monoalkyl and dialkyl ethers derived therefrom,especially the monomethyl and dimethyl ethers and the monoethyl anddiethyl ethers, esters derived from aliphatic (C₁-C₆) carboxylic acidsand either (C₁-C₈)-alkanols or (C₁-C₈)-alkandiols or(C₁-C₆)-alkoxy-(C₁-C₈)-alkanols, such as ethyl acetate, hydroxyethylacetate, alkoxyethyl acetate, n-butyl acetate, amyl acetate, propyleneglycol monoalkyl ether acetate, especially propylene glycol monomethylether acetate, propylene glycol monomethyl ether, ethyl lactate, ethylpyruvate, ethers such as tetrahydrofuran and dioxane, ketones such asmethyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone,cyclopentanone, and cyclohexanone, N,N-dialkylcarboxyamides such asN,N-dimethylformamide and N,N-dimethylacetamide, and also1-methyl-pyrrolidin-2-one and butyrolactone as well as any desiredmixture thereof. Among them, the glycol ethers, aliphatic esters andketones are preferred.

Ultimately, the selection of the solvent or solvent mixture depends onthe coating process used, on the desired layer thickness and on thedrying conditions. The solid content of the solution is preferably about5-60% solids, particularly about 10-50% solids.

The composition according to the present invention may be coated ontothe substrate by any method without particular limitation, and thecoating method may be properly selected by taking into considerationpurposes and the like.

According to a preferred embodiment of the present invention, thechemically amplified radiation sensitive composition of the presentinvention is used as a photoresist material on a semiconductorsubstrate. Examples of substrates referred to herein include all thosematerials for production of capacitors, semiconductors, multi-layerprinted circuits or integrated circuits. Specific mention should be madeof silicon substrates, silicon oxide, silicon oxynitride, titaniumnitride, tungsten nitride, tungsten silicide, aluminum, phosphor-spin-onglass, boron-phosphor-spin-on-glass, gallium arsenide, indium phosphide,and the like. In addition, these substrates may be coated with thinfilms of organic antireflective coatings consisting of organic polymersand a dye absorbing at the exposure wavelength. Furthermore, suitablesubstrates are those known from the production of liquid-crystaldisplays, such as glass or indium tin oxide, and also metal plates andsheets, as well as bimetallic or trimetallic sheets or electricallynon-conducting which are coated with metals or paper. These substratesmay be thermally pretreated, superficially roughened, incipiently etchedor pretreated with chemicals to improve desired properties, such asincrease of the hydrophilic nature, or to improve adhesion between thephotoresist and the substrate. Preferably used adhesion promoters forsilicon or silicon oxide substrates are adhesion promoters of theaminosilane type, such as hexamethyldisilazane, or3-aminopropyltriethoxysilane.

The chemically amplified radiation sensitive composition according tothe present invention may also be used as radiation sensitive coatingsfor the production of photochemical recording layers, such as printingplates for letterpress printing, including lithographic printing, screenprinting and flexographic printing. Especially useful is theirapplication as radiation sensitive coatings on aluminum plates, whichhave been surface grained, anodically oxidized and/or silicatized, andzinc or steel plates, which have optionally been chromium plated, andpaper or plastic sheets.

Further, the chemically amplified radiation sensitive compositionaccording to the present invention may be used in the manufacture ofthree dimensional microdevices, such as micro actuators, micro gears,and the like using fabrication techniques known to those skilled in theart, such as the LIGA process. The (a) positive-working or (b)negative-working chemically amplified radiation sensitive compositionsaccording to the present invention is coated onto a substrate followedby drying to form a layer having a thickness of about 0.1 to 100 μm,preferably about 0.3 to 10 μm, depending upon applications. Thereafter,the coated substrate is exposed to actinic radiation. Suitable radiationsources are conventional broadband radiation sources, such as metalhalide lamps, carbon arc lamps, xenon lamps and mercury vapor lamps,which may be filtered to yield narrow band emission, or excimer lasers,such as KrF excimer lasers, or ArF lasers, but also electron beams, ionbeams, or x-rays. Particularly preferred are KrF excimer lasers, or ArFlasers emitting at 248 nm and 193 nm, respectively, and electron beamsas well as x-rays.

Further, according to another aspect of the present invention, there isprovided a process for producing a recording medium, comprising thesteps of: dissolving the composition of the present invention in asolvent; coating the solution onto a substrate to form a radiationsensitive layer; and removing the solvent by evaporation.

According to this aspect of the present invention, the chemicallyamplified radiation sensitive composition may be coated onto thesubstrate by spray coating, flow coating, roller coating, spin coating,dip coating or the like. Thereafter, the solvent is removed byevaporation to leave the radiation sensitive layer as a film on thesubstrate. The removal of the solvent can be achieved by heating thefilm to about 150° C. Alternatively, a method may be used whichcomprises coating the radiation sensitive composition onto anintermediate substrate material by the above method and thentransferring the coating onto a contemplated substrate by pressure, heator a combination of pressure with heat. All materials suitable assubstrate materials may be used as materials for the intermediatesubstrate. Thereafter, the layer thus formed is exposed image by image.After the exposure, the layer is heated at 60 to 150° C. for 30 to 300sec in order to sensitize the latent image.

The layer is then treated with a developer. In the development, in thecase of the positive-working radiation sensitive composition, theexposed regions are dissolved and removed, while, in the case of thenegative-working radiation sensitive composition, the unexposed regionsare dissolved and removed. As a result, images of the master, which hasbeen exposed image by image, are left on the substrate. The heating ofthe layer before the development step increases the sensitivity of therecording material according to the present invention and is essentialto produce extremely fine patterns. If the heating step is carried outat temperatures which are too low, adequate sensitivity of the materialis not achieved, or, depending on the activation energy of thechemically amplified reaction, complete failure of the image formationmay be observed. If the selected temperature is too high, impairment ofthe resolving power may result.

Suitable developers are aqueous solutions which contain hydroxides,particularly hydroxides of tetraalkyl ammonium ions, such as tetramethylammonium hydroxide. Other developers include the aqueous solutionscontaining aliphatic amines, or N-containing heterocycles, or silicates,metasilicates, hydrogenphosphates, and dihydrogenphosphates, carbonatesor hydrogen carbonates of alkali metals, alkaline earth and/or ammoniumions, and also ammonia and the like. Developers free of metals usefulfor microelectronic device manufacturing are described in U.S. Pat. No.4,141,733, U.S. Pat. No. 4,628,023, or U.S. Pat. No. 4,729,941, or EP-A23,758, EP-A 62,733 and EP-A 97,282, and these developers may also beused. The content of these substances in the developer solution is ingeneral about 0.1 to 15% by weight, preferably about 0.5 to 5% byweight, based on the weight of the developer solution. Developers whichare free of metals are preferably used. Small amounts of a wetting agentmay be added to the developer in order to facilitate the stripping ofthe soluble portions of the recording layer.

EXAMPLES

The present invention will be described in more detail with reference tothe following examples, though it is not limited to these examples only.

Synthesis Example 101 Preparation of diphenyl 4-t-butylphenyl3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 101)

A column having a length of 55 cm and an inner diameter of 5 cm waspacked with 700 g of Amberlyst A-26 (tradename) dispersed in methanol inits chloride form. 3,000 ml of methanol was added to 3,000 ml of a 54%aqueous solution of tetramethyl ammonium hydroxide. This alkali solutionwas used to convert the chloride form of the Amberlyst ion-exchangeresin to its hydroxide form. The column was then washed with methanoluntil the solution withdrawn from the column became neutral.

39.93 g (0.1 mol) of diphenyl 4-t-butylphenyl bromide was dissolved inabout 50 ml of methanol. The solution was passed through the column byelution with methanol at a rate of 30 ml/hour. The eluate was monitoredusing a potentiometer and occasionally tested for the absence of bromideions using an aqueous silver nitrate solution. Next, the concentrationof the hydroxyl group was determined by titration with 0.1N HCl. Theyield of diphenyl 4-t-butylphenyl hydroxide was about 100%. The solutionwas adjusted to 1.0 mmol/g diphenyl 4-t-butylphenyl hydroxide. Withstirring, to 500 g (50 mmol) of the diphenyl 4-t-butylphenyl hydroxidewas added dropwise 10.45 g (50 mmol) of freshly3,3,3,2,1,1-hexafluoropropane sulfonic acid diluted with 50 ml ofmethanol at room temperature. The mixture was stirred at roomtemperature for 24 hours. The solvent was removed by evaporation. Theoil (27.5 g (about 100%)) thus obtained was crystallized to give purediphenyl 4-t-butylphenyl 3,3,3,2,1,1-hexafluoropropane sulfonate.

The purity was measured by HPLC and found to be >99%.

¹H-NMR (CDCl₃): 1.44 (s, 9H,4-t-butyl), 5.23-5.41 (d[m], 1H, CHF),7.62-7.78 ppm (m, 14H, aromatic).

Synthesis Example 102 Preparation of triphenyl sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 102)

91.03 g (0.45 mol) of diphenyl sulfoxide was dissolved in 1300 ml ofbenzene in a 2-liter three-neck round-bottom flask equipped with astirrer, a thermometer, a dropping funnel, a condenser, and a nitrogeninlet. The mixture was cooled to 4° C. with vigorous stirring. Asolution of 189.0 g of (0.90 mol) trifluoroacetic anhydride and 104.4 g(0.45 mol) of 1,1,1,2,3,3-hexafluoropropane sulfonic acid was addeddropwise thereto, while the temperature was maintained under icecooling. After completion of the addition, the mixture was stirred for 1hour. The temperature was returned room temperature, followed bystirring for additional 15 hours. After standing overnight, two separatephases were formed. The upper phase was removed and discarded. The oilybottom phase of approximately 500 ml volume was dropped into 2000 ml ofdiethyl ether, upon which a semi-crystalline deposit was formed. Theether was decanted, and the precipitate was dissolved in a minimumamount of dichloromethane. The solution was added dropwise to 1000 ml ofvigorously stirred diethyl ether to reprecipitate the product. Aftercompletion of the addition, stirring was continued for 2 hours. Afterthe solid was separated from diethyl ether, this procedure was repeatedonce more to enhance the crystallinity of the product. The mixture wasfiltered, and the semi-crystals were collected yielding 165.0 g of crudesulfonium salt. The melting point of the crude sulfonium salt was104-109° C. Depending on the purity, the crystals can be eitherrecrystallized from ethyl acetate or dissolved in the minimum amount ofdichloromethane and purified by column chromatography on silica gelusing a 95:5 dichloromethane-methanol mixture to perform purification.The first fractions containing unreacted diphenyl sulfoxide werediscarded. After collection of the main fractions, the solvent wasevaporated to leave 135.5 g (yield 60.9%) of triphenyl sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate as white crystals (m.p. 111-112°C.).

¹H-NMR (CDCl₃): δ=5.24-5.41 (d[m], 1H), 7.63-7.74 (m, 15H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 103 Preparation of tris-(4-t-butylphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 103)

48.18 g (0.15 mol) of bis-(4-t-butylphenyl) sulfoxide (prepared fromdiphenyl sulfide and t-butyl bromide via FeCl₃ catalyzed alkylation andsubsequent oxidation with 2-chlorobenzoic acid) was dissolved in 400 mlof 4-t-butylbenzene in a 1-liter three-neck round-bottom flask equippedwith a stirrer, a thermometer, a dropping funnel, a condenser and anitrogen inlet. The mixture was cooled to 4° C. with vigorous stirring.A solution of 63.0 g (0.30 mol) of trifluoroacetic anhydride and 34.8 g(0.15 mol) of 1,1,1,2,3,3-hexafluoropropane sulfonic acid was addeddropwise thereto, while the temperature was maintained under icecooling. After completion of the addition, the mixture was stirred for 1hour. The temperature was returned to room temperature, followed bystirring for additional 15 hours. After standing overnight, two separatephases were formed. The upper phase was removed and discarded. The oilybottom phase of approximately 150 ml volume was diluted with 800 ml ofdiethyl ether, and washed twice with water and a sodium bicarbonatesolution. The organic phase was dried over MgSO₄. After removal of thesolvent, a semicrystalline solid was obtained. The semicrystalline solidwas recrystallized from diethyl ether. Thus, white crystals oftris-(4-t-butylphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate(42%) (m.p. 238-240° C.) was obtained.

¹H-NMR (CDCl₃): δ=1.34 (s, 27H), 5.32-5.53 (d[m], 1H), 7.62-7.65 (d,6H), 7.68-7.71 (d, 6H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Examples 104 to 108

The following sulfonium salts were prepared in substantially the samemanner as in the above synthesis examples (PAGs 104-108).

Tris-(4-methylphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate(PAG 104)

¹H-NMR (CDCl₃): δ=2.42 (s, 9H), 5.24-5.41 (d[m], 1H), 7.43-7.45 (d, 6H),7.51-7.53(d, 6H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

4-Methylphenyl-diphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (PAG 105)

¹H-NMR (CDCl₃): δ=2.45 (s, 3H), 5.24-5.40 (d[m], 1H), 7.44-7.46 (d, 2H),7.51-7.53 (d, 2H), 7.63-7.76 (m, 10H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Bis-(4-methylphenyl)phenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (PAG 106)

¹H-NMR (CDCl₃): δ=2.43 (s, 6H), 5.23-5.40 (d[m], 1H), 7.44-7.46 (d, 4H),7.52-7.54 (d, 4H), 7.65-7.78 (m, 5H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Bis-(4-t-butylphenyl)phenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (PAG 107)

¹H-NMR (CDCl₃): δ=1.34 (s, 18H), 5.32-5.54 (d[m], 1H), 7.63-7.79 (m,13H) ppm.

4-Cyclohexylphenyl-diphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (PAG 108)

¹H-NMR (CDCl₃): δ=1.12-1.74 (m, 10H), 2.41-2.43 (m, 1H), 5.28-5.50(d[m], 1H), 7.24-7.27 (d, 4H), 7.63-7.79 (m ,9H) ppm.

Synthesis Example 109 Preparation of tris-(4-butoxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 109)

To a stirred solution of 60.0 g (0.164 mol) of bis-(4-t-butoxyphenyl)sulfoxide in 26.8 g (0.34 mol) of pyridine and 400 ml of tetrahydrofuranwas dropped 75.6 g (0.34 mol) of trimethylsilyl3,3,3,2,1,1-hexafluoropropane sulfonate while keeping the temperaturebelow −5° C. with a salted ice bath. After completion of the addition,the reaction temperature was raised to 5° C., followed by stirring for20 minutes. A Grignard solution was prepared from 8.4 g (0.34 mol) ofmagnesium, 100 g of tetrahydrofuran and 68.6 g (0.38 mol) of 4-t-butoxychlorobenzene, and added dropwise to the above solution at 0° C. Themixture was stirred for 2 hours at this temperature. Then water wasadded to decompose the excess Grignard reagent, and the inorganic saltswere removed by filtration. The solution was concentrated to about 160ml and extracted with a mixture of 1200 ml of dichloromethane, 600 g ofa saturated aqueous solution of ammonium chloride and 600 ml water. Theorganic phase was washed twice with water and dried. The solvent wasremoved to yield an oily product which was then purified by columnchromatography on silica gel using dichloromethane as the eluant. Thus,tris-(4-butoxyphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonatewas obtained as a slightly yellowish powder (m.p. 107° C.). Thestructure was confirmed by ¹H-NMR (CDCl₃) with δ=1.42 (s, 27H),5.14-5.52 (d[m], 1H), 7.17-7.20 (d, 6H) and 7.55-7.60 ppm (d, 6H).

Synthesis Example 110 Preparation oftris-(4-t-butoxycarbonylmethoxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 110)

A solution of 56.8 g (0.08 mol) of tris-(4-butoxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate and 1.86 g (0.008 mol) of3,3,3,2,1,1-hexafluoropropane sulfonic acid in 200 ml of ethanol wasrefluxed for 8 hours with stirring. After evaporation of the solvent,the obtained crude product of tris-(4-hydroxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (yield about 100%) was dissolvedin 160 g of N,N-dimethylformamide and reacted with 55.4 g (0.40 mol) ofanhydrous potassium carbonate and 60.3 g (0.40 mol) of t-butylchloroacetate at 80° C. for 3 hours. The cooled reaction mixture waspoured into 700 ml of water and extracted with dichloromethane. Theorganic phase was washed with water and dried. The solvent was removed.The oily residue was purified by column chromatography on silica gelusing a dichloromethane and methanol as the eluent. The white productwas collected to yield 31.8 g (yield 45%) of analytically puretris-(4-t-butoxycarbonylmethoxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate. The melting point of theproduct was 78° C. The ¹H-NMR spectrum gave the following signals(CDCl₃): δ=1.45 (s, 27H), 4.56 (s, 6H), 5.20-5.56 (d[m], 1H), 7.10-7.13(d, 6H), 7.55-7.60 (d, 6H).

Synthesis Example 111 Preparation of β-oxocyclohexyl 2-norbornyl methylsulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 111)

To a solution of 14.14 g (0.106 mol) of 2-chlorocyclohexane in 100 ml ofethanol was added dropwise 50 ml of a 15% solution of methylmercaptanesodium salt. The mixture was stirred for 3 hours. Then 600 ml water wasadded, and the mixture was extracted with dichloromethane. The organicphase was dried, and the solvent was removed to yield crudeP-oxocyclohexyl methyl sulfide, which was purified by distillation (b.p.45-47° C./0.3 mmHg). 2.0 g (15.6 mmol) of this product was dissolved in10 ml of nitromethane and added dropwise with 20 g (114 mmol) of2-bromonorbornane and stirred at room temperature for 1 hour. Afterthat, a solution of 1.89 g (15.6 mmol) of silver3,3,3,2,1,1-hexafluoropropane sulfonate dissolved in 400 ml ofnitromethane was added dropwise to the reaction mixture and stirred forthree hours at room temperature. The silver bromide was removed byfiltration. The filtrate was concentrated to 50 ml, and then addeddropwise to 600 ml of diethyl ether. The precipitated solid wascollected, washed with ether and recrystallized from ethyl acetate. Theyield of β-oxocyclohexyl 2-norbornyl methyl sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate was 1.67 g.

¹H-NMR (CDCl₃): δ=1.33-2.28 (m, 16H), 2.30-3.10 (m, 5H), 3.65-3.77 (m,1H), 4.95-5.53 ppm (2m, 2H).

Synthesis Example 112 Preparation of bis-(4-cyclohexylphenyl) iodonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 112)

A 500 ml three-neck round bottom flask equipped with a stirrer, athermometer, a dropping funnel, a condenser, and a nitrogen inlet wascharged with 43 g (0.20 mol) of potassium iodate, 69.2 g (0.43 mol) ofcyclohexylbenzene and 43 ml acetic anhydride. The mixture was cooled to−5° C. A mixture of 43 ml of acetic anhydride and 30.1 ml concentratedsulfuric acid was added dropwise thereto with vigorous stirring. Duringthe addition, the reaction temperature was kept below 5° C. After theend of the addition, the temperature of the reaction solution wasreturned to room temperature over a period of 2 to 3 hours. Theresulting mixture was left for 48 hours and cooled to 5° C. 100 g of a1:1 ice/water mixture was added with stirring. During this operation,the reaction temperature was kept below 10° C. Precipitated crystals ofpotassium salts were removed by filtration, and the mixture wasextracted twice with petroleum ether. To the remaining aqueous solutionwas added dropwise 45 g of ammonium bromide dissolved in 100 ml waterwith stirring. The precipitate of bis-(4-cyclohexylbenzene)iodoniumbromide was isolated by filtration, washed, and dried.

15.26 g (28.5 mmol) of the bromide was dissolved in 100 ml ofdichloromethane and 7.3 g (34.2 mmol) of 1,1,1,2,3,3-hexafluoropropanesulfonic acid was added. The mixture was stirred at reflux for 6 hours.Hydrogen bromide evolved. After cooling, the reaction mixture was washedtwice with a 2.5% aqueous solution of tetramethyl ammonium hydroxide andthen dried. The solvent was then removed. The yellowish residue wasrecrystallized from an isopropanol/isopropyl ether mixture to give 12.2g (63%) of bis-(4-cyclohexylphenyl) iodonium3,3,3,2,1,1-hexafluoropropane sulfonate. This product had a meltingpoint of 97° C.

¹H-NMR (CDCl₃): δ=1.12-1.76 (m, 20H), 2.41-2.44 (m, 2H), 4.96-5.18 (m,1H), 7.16-7.19 (d, 4H), 7.78-7.81 (d, 4H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Examples 113-115

The following sulfonium salts were synthesized in substantially the samemanner as in the above synthesis examples (PAGs 113-115).

Diphenyl iodonium 3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 113)

¹H-NMR (CDCl₃): δ=4.98-5.20 (d[m], 1H), 7.61-7.78 (m, 10H) ppm.

Bis-(4-methylphenyl) iodonium 3,3,3,2,1,1-hexafluoropropane sulfonate(PAG 114)

¹H-NMR (CDCl₃): δ=2.42 (s, 18H), 4.96-5.18 (d[m], 1H), 7.41-7.43 (d,4H), 7.50-7.52 (d, 4H) ppm.

Bis-(4-t-butylphenyl) iodonium 3,3,3,2,1,1-hexafluoropropane sulfonate(PAG 115)

¹H-NMR (CDCl₃): δ=1.34 (s, 18H), 5.00-5.22 (d[m], H), 7.62-7.65 (d, 6H),7.68-7.71 (d, 6H) ppm.

Synthesis Example 116 Preparation of 4-methylphenyl phenyl iodonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 116)

To a stirred suspension of 4.40 g (20 mmol) of iodosylbenzene in 100 mlof dichloromethane was added dropwise 4.64 g (20 mmol) of3,3,3,2,1,1-hexafluoropropane sulfonic acid at 0° C. under exclusion ofmoisture. The mixture was stirred at room temperature for 2 hours. Thetemperature was returned to 0° C. again. 1.84 mg (20 mmol) of toluenewas added dropwise. After the addition, stirring was continued at roomtemperature for additional 1 hour. The solvent was evaporated. The oilyresidue was dissolved in diethyl ether. After cooling, crystals of4-methylphenyl phenyl iodonium 3,3,3,2,1,1-hexafluoropropane sulfonatewere obtained. The crystals were washed with hexane.

The yield was 5.2 g.

¹H-NMR (CDCl₃): δ=2.43 (s, 3H), 4.98-5.18 (d[m], 1H), 7.42-7.44 (d, 2H),7.52-7.54 (d, 2H), 7.61-7.78 (m, 5H) ppm.

Synthesis Example 117 Preparation of bis-(4-butoxyphenyl)phenylsulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 117)

To a stirred solution of 60.0 g (0.174 mol) of bis-(4-t-butoxyphenyl)sulfoxide in 26.8 g (0.34 mol) of pyridine and 400 ml of tetrahydrofuranwas dropped 75.6 g (0.34 mol) of trimethylsilyl3,3,3,2,1,1-hexafluoropropane sulfonate while keeping the solutiontemperature below −5° C. with a salted (sodium chloride) ice bath. Aftercompletion of the addition, the reaction temperature was raised to 5°C., followed by stirring for 20 minutes. A Grignard reagent solution wasprepared from 8.4 g (0.34 mol) of shaved magnesium, 100 g oftetrahydrofuran and 42.8 g (0.38 mol) of chlorobenzene, and addeddropwise to the above solution at 0° C. The mixture was stirred for 2hours at this temperature. Then water was added to decompose the excessGrignard reagent. The inorganic salts were removed by filtration. Thesolution was concentrated to about 160 ml and extracted with 1200 ml ofdichloromethane, 600 g of a saturated solution of ammonium chloride and600 ml of water. The organic phase was washed twice with water anddried. The solvent was removed to yield an oily product which wasapplied to column chromatography on silica gel using dichloromethane asthe developing solvent. The corresponding fractions were combined andconcentrated to obtain bis-(4-butoxyphenyl)phenyl sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate as a slightly yellowish powder(m.p. 102° C.). The structure was confirmed by ¹H-NMR (CDCl3) withδ=1.42 (s, 18H), 5.32-5.54 (d[m], 1H), 7.20-7.23 (d, 4H), and 7.63-7.79ppm (m, 9H).

Synthesis Example 118 Preparation ofbis-(4-methylphenyl)4-cyclohexylphenyl sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 118)

A mixture of 10.36 g (4.5 mmol) of ditolyl sulfoxide with 7.21 g (4.5mmol) of 4-cyclohexylbenzene was placed in a 125 ml flask. Then 20 ml ofa previously prepared phosphorus pentaoxide/metanesulfonic acid reagent(prepared by dissolving 36 g of phosphorus pentaoxide in 360 g ofmethanesulfonic acid) was added thereto while stirring with a magneticstirrer. The mixture was heated to about 50° C. Thus, a dark brownsolution was obtained. After the exothermic reaction ceased, the mixturewas stirred at 45° C. for additional 3 hours. The temperature was thenreturned to room temperature, and the mixture was poured into 100 ml ofwater and 100 g of ice. The slightly suspended solution was filtered,followed by addition of 10.44 g (4.5 mmol) of3,3,3,2,1,1-hexafluoropropane sulfonic acid to yield a white oil. Theoil was stirred for 1 hour, and 200 ml of ethyl acetate was addedthereto. The mixture was extracted. The organic phase was washed severaltimes with water, and then dried. The solvent was removed bydistillation. The oily residue was recrystallized from ethyl acetate anddiethyl ether to give 11.5 g of the contemplated material. The structurewas confirmed by ¹H-NMR (CDCl₃) with δ=1.08-1.74 (m, 10H), 2.41-2.43 (m,7H), 5.27-5.48 (d[m], 1H), 7.16-7.19 (d, 2H), 7.43-7.46 (d, 4H),7.50-7.53 (d, 4H), and 7.78-7.80 ppm (d, 2H).

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 119 Preparation of tris-(4-chlorophenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 119)

A mixture of 13.56 g (5.0 mmol) of 4,4′-dichlorophenyl sulfoxide with5.63 g (5.0 mmol) of 4-chlorobenzene was placed in a 125 ml flask. Then20 ml of a previously prepared phosphorus pentaoxide/metanesulfonic acidreagent (prepared by dissolving 36 g of phosphorus pentaoxide in 360 gof methanesulfonic acid) was added thereto while stirring with amagnetic stirrer. A slight exothermic reaction occurred. The system wasfurther heated at 55° C. for 6 hours. This resulted in significant colordevelopment. The system was then cooled to room temperature. Thereaction mixture was poured into 100 ml of water and 100 g of ice. Theslightly suspended solution was filtered, followed by addition of 11.6 g(5.0 mmol) of 3,3,3,2,1,1-hexafluoropropane sulfonic acid to yield ayellow oil. The oil was stirred for 1 hour, and 200 ml ofdichloromethane was added thereto. The mixture was extracted. Theorganic phase was washed several times with water, and then dried. Thesolvent was removed by distillation. The oily residue was recrystallizedfrom ethyl acetate to give 6.5 g of the contemplated material. Thestructure was confirmed by ¹H-NMR (CDCl₃) with δ=5.25-5.52 (d[m], 1H),7.32-7.43 (d, 6H), and 7.63-7.74 (d, 6H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 120 Preparation of tris-(t-butoxycarbonyloxyphenyl)sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 120)

56.8 g (0.08 mol) of tris-(4-butoxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (Synthesis Example 110) and 1.86g (0.008 mol) of 3,3,3,2,1,1-hexafluoropropane sulfonic acid weredissolved in 200 ml of ethanol. The solution was heated under ref luxfor 8 hours with stirring. After removal of the solvent by distillation,the obtained crude product of tris-(4-hydroxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (yield about 100%) was dissolvedin 160 g of N,N-dimethylformamide and reacted with 55.4 g (0.40 mol) ofanhydrous potassium carbonate and 60.3 g (0.40 mol) of di-t-butyldicarbonate at 20° C. for 3 hours. The reaction solution was poured into700 ml of water and extracted with dichloromethane. The organic phasewas washed with water and dried. The solvent was removed bydistillation. The oily residue was purified by column chromatography onsilica gel using a dichloromethane and methanol as the developingsolvent. The white product was collected to yield 31.8 g (yield 45%) ofanalytically pure tris-(4-t-butoxycarbonylmethoxyphenyl) sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate. The melting point of theproduct was 78° C. The ¹H-NMR spectrum gave the following signals(CDCl₃): δ=1.45 (s, 27H), 5.30-5.56 (d[m], 1H), 7.10-7.13 (d, 6H),7.55-7.60 (d, 6H).

Synthesis Example 121 Preparation of 4-methylphenyl dimethyl sulfonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 121)

A mixture of 7.81 g (10.0 mmol) of dimethyl sulfoxide with 9.21 g (10.0mmol) of toluene was placed in a 200 ml flask. Then 40 ml of apreviously prepared phosphorus pentaoxide/metanesulfonic acid reagent(prepared by dissolving 36 g of phosphorus pentaoxide in 360 g ofmethanesulfonic acid) was added thereto while stirring with a magneticstirrer. A slight exothermic reaction occurred. The system was stirredat room temperature for 6 hours. The reaction mixture was poured into150 ml of water and 150 g of ice. The slightly suspended solution wasfiltered, followed by addition of 23.2 g (10.0 mmol) of3,3,3,2,1,1-hexafluoropropane sulfonic acid to yield a colorless oil.The oil was stirred for 1 hour, and 200 ml of dichloromethane was addedthereto. The mixture was extracted. The organic phase was washed severaltimes with water, and then dried. The solvent was removed bydistillation. The oily residue was recrystallized from isopropyl alcoholto give 6.5 g of the contemplated material. The structure was confirmedby ¹H-NMR (CDCl₃) with δ=2.41 (s, 3H), 3.46 (s, 6H), 5.32-5.56 (d[m],1H), 7.42-7.45 (d, 2H), 7.50-7.53 (d, 2H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 122 Preparation of 4-hdroxy-3,5-dimethylphenyldiphenyl sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 122)

A mixture of 13.56 g (5.0 mmol) of diphenyl sulfoxide with 5.63 g (5.0mmol) of 4-hydroxy-3,5-dimethylbenzene was placed in a 125 ml flask.Then 20 ml of a previously prepared phosphorus pentaoxide/metanesulfonicacid reagent (prepared by dissolving 36 g of phosphorus pentaoxide in360 g of methanesulfonic acid) was added thereto while stirring with amagnetic stirrer. A slight exothermic reaction occurred. The system wasfurther heated at 55° C. for 6 hours. This resulted in significant colordevelopment. The system was then cooled to room temperature. Thereaction mixture was poured into 100 ml of water and 100 g of ice. Theslightly suspended solution was filtered, followed by addition of 11.6 g(5.0 mmol) of 3,3,3.2,1,1-hexafluoropropane sulfonic acid to yield anyellow oil. The oil was stirred for 1 hour, and 200 ml ofdichloromethane was added thereto. The mixture was extracted. Theorganic phase was washed several times with water, and then dried. Thesolvent was removed by distillation. The oily residue was recrystallizedfrom ethyl acetate to give 6.5 g of the contemplated material. Thestructure was confirmed by ¹H-NMR (CDCl₃): δ=2.33 (s,6H), 5.34-5.51(d[m], 1H), 7.35 (s, 1H), 7.41 (s, 1H), 7.63-7.79 ppm (m, 10H.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 123 Preparation of 2-phenylcarbonylmethyl dimethylsulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 123)

18.13 g (100 mmol) of 2-phenylcarbonylmethyl dimethyl chloride wasdissolved in 350 ml of chloroform, and 24.36 g (105 mmol) of3,3,3,2,1,1-hexafluoropropane sulfonate was added to the solution. Themixture was refluxed for 6 hours. During the reflux, hydrogen chloridewas evolved. The reaction mixture was cooled, extracted with water, anddried. The solvent was removed by distillation. The resultant solid waspurified by recrystallization from isopropanol and diisopropyl ether.The structure was confirmed by ¹H-NMR (CDCl₃): δ=3.44 (s, 6H), 5.88 (s,2H), 5.34-5.54 (d[m], 1H) 7.62-7.70 ppm (m, 5H).

Synthesis Example 124 Preparation of di-(4-t-butyloxyphenyl) iodonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 124)

6.2 g (0.11 mol) of potassium hydroxide was dissolved in 250 ml ofethanol. 27.2 g (0.05 mol) of bis-(4-hydroxyphenyliodonium)3,3,3,2,1,1-hexafluoropropane sulfonate (prepared from a metathesisreaction of chloride) was added to the solution. The mixture was stirredfor 3 hours. The solution was then heated to 50° C., and 15.1 g (0.11mol) of t-butyl bromide was added dropwise thereto. The mixture washeated under reflux for 6 hours. The precipitates were removed byfiltration. The solvent was removed from the filtrate by distillation.The residue was dissolved in 250 ml of ethyl acetate. The solution waswashed several times with water, and then dried. The solvent was removedto obtain a yellow oil. The contemplated material was obtained byrecrystallization from diethyl ether. The structure was confirmed by¹H-NMR (CDCl₃): δ=1.43 (s, 18H), 5.00-5.30 (d[m], 1H), 7.17-7.21 (d,4H), 7.55-7.59 ppm (d, 4H).

Synthesis Example 125 Preparation ofdi-(4-t-butylcarbonyloxymethyloxyphenyl) iodonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 125)

The title compound was obtained in substantially the same manner as inthe above synthesis example, except that t-butyl bromide was replacedwith an equal amount of t-butyl bromoacetate. The structure wasconfirmed by ¹H-NMR (CDCl₃): δ=1.42 (s, 18H), 4.55 (s, 4H), 4.94-5.18(d[m], 1H), 7.10-7.14 (d, 4H), 7.56-7.60 ppm (d, 4H).

Synthesis Example 126 Preparation of 4-t-butylphenyl phenyl iodonium3,3,3,2,1,1-hexafluoropropane sulfonate (PAG 126)

4.4 g (20 mmol) of iodosylbenzene was suspended in 100 ml of drydichloromethane. The suspension was cooled to 0° C. with stirring. 4.65g (20 mmol) of 3,3,3,2,1,1-hexafluoropropane sulfonic acid (optionallydistilled) was added at the same temperature thereto under exclusion ofmoisture. The mixture was stirred at room temperature for 3 hours. Thetemperature of the mixture was returned to 0° C., and 2.68 g (20 mmol)of 4-t-butylbenzene was added thereto at that temperature. Thetemperature of the mixture was returned to room temperature, followed bystirring for 6 hours. Thereafter, the insolubles were removed byfiltration. The solvent was removed from the filtrate. The oily residuewas purified by recrystallization (twice) from diethyl ether. Thestructure was confirmed by ¹H-NMR (CDCl₃): δ=0.81 (s, 9H), 4.98-5.22(m[d], 1H), 7.18-7.23 (d, 2H), 7.58-7.65 ppm (m, 7H).

Example 101

A copolymer of 4-hydroxystyrene and 4-t-butyloxycarbonylstyrene wasprepared by reacting monodisperse poly-4-hydroxystyrene withdi-t-butylcarbonate. The copolymer had a molecular weight of 8,700 witha polydispersity of 1.18 as determined by GPC using polystyrene as thestandard. The molar ratio of4-hydroxystyrene:4-t-butyloxycarbonylstyrene was 7:3 as concluded frominspection of the ¹H NMR spectrum. This copolymer will be hereinafteroften referred to as “POLY 101.”

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.3 g of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate,

0.02 of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered through a teflon filter having a pore diameterof 0.1 μm, spin coated on a silicon wafer pre-coated with DUV-18, anantireflective coating provided by Brewer Science at a film thickness of115 nm (bake temperature: 200° C.), at 3,000 revolutions and dried at90° C. for 60 seconds on a hot plate to remove the solvent. Thus, a 0.72μm-thick thin film was obtained. The recording material thus obtainedwas imagewise exposed using a mask providing lines and spaces patternsdown to 0.10 μm per image with a DUV stepper Nikon NSR 2005 EX 10B,having a numerical aperture (NA) of 0.55 during exposure and a coherencefactor ( a ) of 0.55 with a dose of 18 mJ/cm². The medium was baked at100° C. for 90 seconds to develop the latent image, and then processedat 23° C. by puddle development with AZ MIF 300, a surfactant freedeveloper containing 2.38% by weight of tetramethyl ammonium hydroxideprovided by Clariant Japan K.K. A defect-free image of the mask withhigh edge stability was obtained, structures <0.25 μm being resolvedfaithfully to detail and the width ratio (linearity of the resist) ofnominally equal lines/space structures being virtually constant in therange between 1.00 μm and 0.25 μm. The resist profile was almostvertical and very smooth, as neither edge roughness nor standing waveswere observed.

Example 102

Radical copolymerization of 4-acetoxystyrene, styrene andt-butylmethacrylate was carried out in the presence of2,2-azo-bis-isobutyronitrile as a polymerization initiator, followed byhydrolysis of the acetate groups with an aqueous ammonium acetatesolution to prepare a terpolymer of 4-hydroxystyrene, styrene andt-butyl methacrylate. The terpolymer had a molecular weight of 14,200with a polydispersity of 1.69 as determined by GPC using polystyrene asthe standard, and the molar ratio of4-hydroxystyrene:styrene:t-butylmethacrylate was 7:2:1 as determined by¹H NMR. This polymer will be hereinafter often referred to as “POLY102.”

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.3 g of diphenyl iodonium 3,3,3,2,1,1-hexafluoropropane sulfonate,

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered, spin-coated on a HMDS treatedsilicon wafer and baked for 60 seconds on a hot plate at 130° C. toyield a film thickness of 0.82 μm. The recording material was exposed inthe same manner as in Example 101. The dose was 27 mJ/cm². The film wasthen baked at 130° C. for 90 seconds. Subsequent development asdescribed in Example 101 resolved line and space patterns below 0.23 μm.From scanning electron microscope (SEM) inspection, it was concludedthat the linewidth of isolated and dense lines was almost equal, i.e.the dense to iso bias was negligible. Isolated line patterns wereresolved down to 0.16 μm.

Example 103 and Comparative Examples 101 and 102

Radical polymerization of 4-t-butyloxystyrene was carried out in thepresence of 2,2-azo-bis-isobutyronitrile as a polymerization initiator,followed by partial hydrolysis of the t-butyloxy groups with aconcentrated aqueous hydrogen chloride solution to prepare4-hydroxystyrene with 12% of the t-butyloxy styrene units being leftintact. This copolymer was then reacted with ethyl vinyl ether in thepresence of p-toluenesulfonic acid as a catalyst to prepare a terpolymerof 4-hydroxystyrene, 4-(1-ethoxyethoxy)styrene and 4-t-butoxystyrene.The terpolymer thus obtained had a molecular weight of 23,400 with apolydispersity of 2.14 as determined by GPC using polystyrene as thestandard, and the molar ratio of 4-hydroxystyrene:styrene:t-butylmethacrylate styrene was about 6.7:2.2:1.1 as measured by ¹H NMR. Thispolymer will be hereinafter often referred to as “POLY 103.”

The following ingredients were mixed together to prepare solutions of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.3 g (0.61 mmol) of triphenylsulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (Example 103),

0.3 g (0.61 mmol) of triphenyl sulfonium camphor sulfonate (ComparativeExample 101,

0.25 g (0.61 mmol) of triphenyl sulfonium trifluoromethane sulfonate(Comparative Example 102), hereinafter often referred to as“triphenylsulfonium triflate”),

0.02 g of triphenyl sulfonium acetate,

0.05 g of 9-anthramethyl acetate (DUV absorber),

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate

The solutions were filtered, and spin-coated on three silicon wafers,which have been precoated with an experimental antireflective coatingprovided by Clariant Japan K.K. at a film thickness of 60 nm (baketemperature: 220° C.). The resist films were baked for 60 seconds on ahot plate at 130° C. to yield a film thickness of 0.71±0.02 μm.

The recording materials were exposed as described in Example 101(NA=0.50, σ=0.50) and then baked at 105° C. for 60 seconds. Developmentwas done as described in Example 101. The following results wereobtained (Table 101; rating was added in parenthesis (1)=best, (2)intermediate, (3)=poor):

TABLE 101 Comparative Comparative Example 103 Example 101 Example 102Dose (mJ/cm²) 18 (1) 29 (3) 18 (1) Dense Line Resolution 0.18 (1) 0.26(3) 0.18 (1) (μm) Isolated Line 0.17 (1) 0.19 (2) 0.20 (3) Resolution(μm) Dense Line DOF @ 0.22 μm 1.4 (1) 0.0 (3) 1.1 (2) (μm) Isolated LineDOF @ 1.0 (1) 0.6 (3) 0.7-0.8 (2) 0.22 μm (μm) Dense/iso bias @ 0.22 17(1) Na (3) 31 (2) μm (μm)

Remarks: The dose is defined as the exposure energy to delineate equallines and spaces of 0.22 μm pattern width. The dense line resolution isdefined as the smallest equal lines and spaces patterns fully reproducedat that dose. The isolated line resolution is defined as the smallestisolated line pattern without top film loss of the line at that dose.The dense line DOF is defined as the depth of focus of equal lines andspaces at that dose. The isolated line DOF is defined as the depth offocus of isolated lines at that dose. The dense/iso bias is defined asthe linewidth difference between dense lines and isolated lines at thatdose.

These results clearly demonstrate that the resist material using theresist material of the present invention has the best lithographicperformance among these three samples.

Example 104 and Comparative Examples 103 and 104

Monodisperse poly-4-hydroxystyrene (Nippon Soda Co., Ltd., Mw=12,000,polydispersity=1.16) was reacted with 2-chloroethyl vinyl ether in thepresence of p-toluenesulfonic acid as a catalyst to prepare a copolymerof 4-hydroxystyrene and 4-(1-(2-chloroethoxy)ethoxy)styrene. Thecopolymer had a molecular weight of 13,700 with a polydispersity of 1.21as determined by GPC using polystyrene as the standard, and the molarratio of 4-hydroxystyrene: 4-(1-(2-chloroethoxy)ethoxy)styrene was7.1:2.9 as measured by ¹H NMR. This polymer will be hereinafter oftenreferred to as “POLY 104.”

The following ingredients were mixed together to prepare three solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.25 g of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate(Example 104),

0.25 g of triphenyl sulfonium triflate (Comparative Example 103),

0.25 g of triphenyl sulfonium propane sulfonate (Comparative Example104),

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solutions thus obtained were filtered, spin coated on two HMDStreated silicon wafers each (total 6 wafers), baked for 90 seconds on ahot plate at 110° C. to yield a thin layer having a thickness of0.75±0.02 μm. The recording material was exposed as described in Example101 (NA=0.55, σ=0.55). The dose was as indicated in Table 102. While oneof each wafer was placed immediately on a hot plate and baked for 90seconds at 90° C. (Test A), the second wafers were stored in the cleanroom for 60 minutes and then baked under the same conditions (Test B).Next, these wafers were developed as described in Example 101.

The results are compiled in Table 102.

TABLE 102 Comparative Comparative Example 104 Example 103 Example 104Test A Dose (mJ/cm²) 22 (2) 20 (1) 37 (3) Dense Line Resolution 0.17 (1)0.18 (2) 0.21 (3) (μm) Isolated Line 0.17 (1) 0.19 (2) 0.19 (2)Resolution (μm) Dense Line DOF @ 0.22 μm 1.4-1.5 1.1 (2) 1.1 (2) (μm)Isolated Line DOF @ 1.0 (1) 0.6 (3) 0.7-0.8 (2) 0.22 μm (μm) Dense/isobias @ 0.22 17 (1) 30 (3) 27 (2) μm (nm) T-top None (1) None (1) None(1) Test B (after one hour) Dose (mJ/cm²) 22 (1) 21 (2) 34 (3) DenseLine Resolution 0.17 (1) 0.18 (2) 0.22 (3) (μm) Isolated Line 0.17 (1)0.21 (2) 0.21 (2) Resolution (μm) Dense Line DOF @ 0.22 μm 1.4-1.5 (1)0.9 (2) 0.6 (3) (μm) Isolated Line DOF @ 0.9 (1) 0.4 (3) 0.6 (2) 0.22 μm(μm) Dense/iso bias @ 0.22 19 (1) 37 (3) 32 (2) μm (nm) T-top None Yes,slight Yes, medium

Remarks: The definition of the test items is the same as given inExample 103. T-top indicates formation of an insoluble phase on top ofthe resist.

These results demonstrate superior performance of the resist material ofthe present invention (Test A) and superiority in dimensional stabilityupon delay time changes (Test B).

Example 105

Monodisperse poly-4-hydroxystyrene (manufactured by Nippon Soda Co.,Ltd., Mw=2,000, polydispersity=1.16) was reacted with dihydropyran and aminor amount of α, ω-triethylene glycol divinyl ether in the presence ofp-toluenesulfonic acid to prepare a copolymer of 4-hydroxystyrene and4-tetrahydropyranyloxystyrene partially crosslinked by α, ω-triethyleneglycol divinyl ether. The copolymer had an average molecular weight of7,500 with an essentially trimodal molecular weight distribution atabout 2,300, 4,600 and 7,000 and a minor amount of higher crosslinkedparts as determined by GPC with polystyrene as the standard, and themolar ratio of 4-hydroxystyrene: 4-tetrahydropyranyloxystyrene wasroughly 6.9:3.1 as measured by ¹H NMR. This polymer will be hereinafteroften referred to as “POLY 105.”

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.42 g of t-butyloxycarbonylphenyl diphenyl sulfonium

3,3,3,2,1,1-hexafluoropropane sulfonate,

0.03 g of tri-n-octylamine,

0.05 g of N,N-dimethylacetamide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered, spin coated on a silicon wafer covered with aphosphor-spin-on-glass layer, which has been pretreated bake at 150° C.,and baked for 90 seconds on a hot plate at 115° C. to yield a thin layerhaving a thickness of 0.65 μm. The recording material was exposed asdescribed in Example 101 (NA=0.55, σ=0.71) using a mask with contacthole patterns down to 0.15 μm at a dose of 55 mJ/cm²and baked for 90seconds at 120° C. Next the material was developed as described inExample 101. Scanning electron microscope (SEM) inspection revealed thatthe recording material resolved 0.20 μm contact holes at a duty ratio of1:1 with a usable depth-of-focus (DOF) of about 0.9 μm. The side wallsof the contact holes were vertically, and virtually no footing wasobserved at the resist/substrate interface.

Example 106

Monodisperse poly-4-hydroxystyrene (manufactured by Nippon Soda Co.,Ltd., Mw=8,000, polydispersity=1.09) was reacted with ethyl vinyl etherin the presence of p-toluenesulfonic acid as a catalyst to prepare acopolymer. The copolymer was reacted with di-t-butylcarbonate in thepresence of triethylamine to prepare a terpolymer of 4-hydroxystyrene,4-(1-ethoxyethoxystyrene) and 4-(t-butyloxycarbonyloxystyrene). Theterpolymer had an average molecular weight of 10,200 with apolydispersity of 1.13 as determined by GPC using polystyrene as thestandard, and the molar ratio of4-hydroxystyrene:4-(1-ethoxyethoxy)styrene:4-t-butyloxycarbonyloxystyrenewas 6.5:3.8:0.7 as measured by ¹H NMR. This polymer will be hereinafteroften referred to as “POLY 106.”

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above terpolymer,

0.35 g of bis-(4-cyclohexylphenyl) phenyl sulfonium

3,3,3,2,1,1-hexafluoropropane sulfonate,

0.02 g of tetrabutyl ammonium hydroxide,

0.02 g of N,N-dicyclohexylamine,

0.004 g of Megafac R-08 (tradename), and

64.2 g of ethyl lactate.

The solution thus obtained was filtered, spin-coated on a HMDS treatedsilicon wafer and baked for 90 seconds on a hot plate at 85° C. to yielda thin layer having a thickness of 0.57 μm. The recording material wasexposed as described in Example 101 (NA=0.55, σ=0.71) using a mask withcontact hole patterns down to 0.15 μm at a dose of 55 mJ/cm²and bakedfor 90 seconds at 120° C. Next the material was developed as describedin Example 101. Exposure was performed as described in Example 101 usingNA=0.50 and a σ-value=0.60 at a dose of 24 mJ/cm². The material wasbaked for 90 seconds at 105° C., and developed with the surfactant-freedeveloper of Example 101 for 60 seconds at 23° C. followed by waterrinsing.

The material resolved dense lines and spaces patterns down to 0.19 μmand isolated lines down to 0.16 μm. The pattern shape was rectangularand no standing waves were observed. The DOF of the isolated patternswas larger than 1.0 μm for 0.18 μm features.

Examples 107 and 108

Radical copolymerization of 4-acetoxystyrene with 4-t-butylacrylate wascarried out in the presence of2,2′-azobis-(4-dimethoxy-2,4-dimethylvaleronitrile) as a polymerizationinitiator, followed by hydrolysis of the acetate groups with an aqueousammonium acetate solution. A part of the hydroxy groups in the copolymerthus obtained were reacted with ethyl vinyl ether in the presence ofp-toluenesulfonic acid as a catalyst to prepare a terpolymer of4-hydroxystyrene, 4-(1-ethoxyethoxystyrene) and 4-t-butylacrylate. Theterpolymer had an average molecular weight of 8,700 with apolydispersity of 1.71 as determined by GPC using polystyrene as thestandard, and the molar ratio of 4-hydroxystyrene:4-(1-ethoxyethoxy)styrene:4-t-butylacrylate was 7.1:1.8:1.1 as measuredby ¹H NMR. This polymer will be hereinafter often referred to as “POLY107.”

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) and e-beam exposure:

9.8 g of the above terpolymer,

0.28 g of bis-(4-cyclohexylphenyl) iodonium3,3,3,2,1,1-hexafluoropropane sulfonate,

0.03 g of triphenyl sulfonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered, spin-coated on two HMDS treated siliconwafers and baked on a hot plate for 90 seconds at 110° C. to yield athin layer having a thickness of 0.53 μm. One of the recording materialswas exposed with excimer laser radiation provided by a Nikon NSR 2005 EX10B stepper with an NA=0.55 and a coherence factor σ=0.80 using a maskwith lines and spaces patterns down to 0.10 μm at a dose of 27 mJ/cm².The other recording material was pattern-wise exposed with e-beamradiation provided from a JEOL JBXX 5DII operating at 50 keV with a spotsize of 10 nm (no proximity correction) at a dose of 18.2 μC/cm². Theexposed wafers were placed on a hot plate and baked for 90 seconds at120° C. The materials were then developed with AZ® MIF 300, a surfactantfree developer containing 2.38% by weight of tetramethyl ammoniumhydroxide provided by Clariant Japan K.K. for 60 seconds at 23° C.followed by water rinsing.

The excimer laser exposed material resolved dense lines and spacespatterns down to 0.18 μm and isolated lines and spaces down to 0.14 μm.The pattern shape was rectangular and only minor standing waves wereobserved. The DOF of the isolated patterns was larger than 1.0 μm for0.16 μm features.

The e-beam exposed material resolved dense lines and spaces down to 0.16μm and isolated lines down to 0.11 μm. The DOF of the isolated patternswas larger than 1.0 μm for 0.15 μm features.

Examples 109 and 110

A terpolymer of 4-hydroxystyrene, 4-(t-butoxystyrene) and4-t-butylcarbonylmethyloxy styrene was prepared by acid hydrolysis ofmonodisperse poly-4-t-butoxystyrene to leave 15% of the butoxy groupsintact. A part of the hydroxy groups in the copolymer were reacted witht-butyl bromoacetate in the pressence of triethylamine as a catalyst.The terpolymer had an average molecular weight of 8,700 with apolydispersity of 1.06 as determined by GPC using polystyrene as thestandard, and the molar ratio of4-hydroxystyrene:4-(t-butoxystyrene:4-t-butylcarbonyloxystrene was7.1:1.4:1.5 as measured by ¹H NMR. This polymer will be hereinafteroften referred to as “POLY 108.” The following ingredients were mixedtogether to prepare a solution of a positive-working chemicallyamplified radiation sensitive composition suitable for DUV (248 nm) andx-ray exposure:

9.8 g of the above terpolymer,

0.2 g of bis-(t-butylcarbonylmethyloxyphenyl) iodonium

3,3,3,2,1,1-hexafluoropropane sulfonate,

0.15 g of tris-(t-butylcarbonylmethyloxyphenyl) sulfonium

3,3,3,2,1,1-hexafluoropropane sulfonate,

0.03 g of tributylammonium pyrovate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of methyl amyl ketone.

The solution was filtered, spin-coated on two HMDS treated siliconwafers and baked on a hot plate (90 sec/100° C.) to yield a thin layerhaving a thickness of 0.72 μm. One of the recording materials wasexposed with excimer laser radiation provided by a Nikon NSR 2005 EX 10Bstepper (NA=0.55, σ=0.55) using a mask with lines and spaces patternsdown to 0.10 μm at a dose of 25 mJ/cm². The other recording material waspatternwise exposed with x-ray radiation provided by a 0.6 GeVsuperconducting beam storage ring with a peak wavelength of 7.5 A usinga Karl Suss XRS-200/3 stepper with a proximity gap of 30 μm at a dose of60 mJ/cm². The x-ray mask had lines and spaces pattern down to 100 nmand was composed of 0.5 μm thick W-Ti absorber on a 2.0 μm thick SiCmembrane. The exposed wafers were baked for 90 seconds at 110° C. anddeveloped as described in Example 101. The excimer laser exposedmaterial resolved dense lines and spaces patterns down to 0.16 μm butthe isolated lines were somewhat unstable and collapsed at geometriesbelow 0.18 μm. The pattern shape was rectangular and only minor standingwaves were observed. The DOF of the isolated patterns was larger than1.0 μm for 0.16 μm features.

The x-ray exposed material resolved dense lines and spaces down to 0.14μm and isolated lines down to 0.14 μm. At smaller geometries thepatterns tended to collapse. The DOF of the isolated patterns was largerthan 1.0 μm for 0.15 μm features.

Example 111

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the terpolymer described in Example 107 (POLY 107),

0.8 g of 4,4′-(1-methylethylidene) bis-[4,1-phenyleneoxy acetic acid]di(1,1-dimethylethyl) ester,

0.2 g of bis-(4-cyclohexylphenyl) phenyl sulfonium

3,3,3,2,1,1-hexafluoropropane sulfonate,

0.03 g of triphenyl sulfonium hydroxide,

0.05 g of a condensation product of 2 moles 9-anthrylmethanol reactedwith 1 mole toluene-1,3-diisocyanate (DUV absorber),

0.004 g of Megafac R-08 (tradename), and

64.2 g propylene glycol monomethyl ether acetate.

The solution was filtered, spin-coated on a HMDS treated silicon waferand baked on a hot plate (90 sec/110° C.) to yield a thin layer having athickness of 0.51 μm, exposed as described previously (NA=0.55) at adose of 34 mJ/cm², baked for 90 seconds at 120° C. and developed.

The material resolved dense lines and spaces patterns down to 0.16 μmand isolated lines down to 0.14 μm. The pattern shape was rectangularand only minor standing waves were observed. The DOF of the isolatedpatterns was about 0.8 μm for 0.16 μm features.

Examples 112 and 113

4-Hydroxystyrene, tetracyclododecyl methacrylate, t-butyl methacrylateand methacrylic acid 2-tetrahydropyranyl ester was radically polymerizedin the presence of 2,2′-azobis(isobutyronitrile) as a polymerizationinitiator to prepare a quaterpolymer. The quaterpolymer had an averagemolecular weight of 13,200 with a polydispersity of 2.4 as determined byGPC using polystyrene as the standard, and the molar ratio of thecomponents was 1.5:3.5:2.5:2.5 as measured by ¹H NMR. This polymer willbe hereinafter often referred to as “POLY 109.”

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure and VDUV (193 nm) exposure:

7.8 g of the quaterpolymer described above,

2.8 g of 4,4′-(1-methylethylidene) bis-[4,1-cyclohexyleneoxy aceticacid] di(1,1-dimethylethyl) ester,

0.2 g of bis-(4-cyclohexylphenyl) iodonium 3,3,3,2,1,1-hexafluoropropanesulfonate,

0.03 g of triethanolamine,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered, spin-coated on two silicon wafers pretreatedwith AZ® KrF-2, a commercially available antireflective coatingavailable from Clariant Japan K.K, baked for 90 seconds at 120° C. toyield a thin layer having a thickness of 0.51±0.02 μm, and one wafer wasexposed as described in Example 101 (NA=0.55, σ=0.80) at a dose of 24mJ/cm², while the other wafer was exposed with an ISI ArF stepper with aNA=0.60 and a σ=0.75 at a dose of 11 mJ/cm². The exposed wafers werebaked for 90 seconds at 125° C. and developed.

The KrF excimer laser exposed material resolved dense lines and spacespatterns below 0.16 μm, isolated lines down to 0.14 μm, but both with aslight tendency to form T-tops. The ArF excimer laser exposed materialshowed the same resolution and pattern characteristics as the KrFexcimer laser exposed material, however, the DOF of 0.18 μm linesexceeded that of the KrF exposed material by 25%.

Examples 114-137

The following radiation sensitive compositions were prepared andprocessed according to the steps indicated in Table 103, where

“Polymer” denotes the polymer used,

“PAG” denotes the PAG (photoacid generator) used,

“DissInh” denotes the dissolution inhibitor used,

“Base” denotes the basic additive used,

“Solv” denotes the solvent used,

“Ratio” denotes the component ratio in parts by weight,

“Substrate” denotes the substrate to be coated with the radiationsensitive composition,

“PB” denotes the applied prebake conditions (temperature/time),

“FT” denotes the film thickness of the radiation sensitive composition,

“Exposure Type” denotes the radiation wavelength employed (ArF=193 nmexcimer laser, KrF=248 nm excimer laser, i-line=365 nm quartz lamp,e-beam=30 keV electron beams, x-ray=1.3 nm),

“Dose” denotes the applied exposure dose (in mJ/cm² for ArF. KrF, I-lineand x-rays and in μC/cm² for e-beam),

PEB denotes the applied post exposure bake conditions(temperature/time),

“Dev” denotes conditions for development (temperature/time) with anaqueous 2.38% tetramethyl ammonium hydroxide solution,

“Res” denotes the resolution capability of dense 1:1 lines and spaces,

“Delay Stability” denotes the linewidth change <10% upon delay betweenexposure and post exposure bake,

“Profile Angle” denotes the angle between the substrate and the sidewallof 0.25 μm line patterns, and

“DOF” denotes the depth of focus of dense 0.25 μm lines.

TABLE 103 EXAMPLE # 114 115 116 117 118 119 Polymer POLY 110 POLY 110POLY 110 POLY 111 POLY 111 POLY 111 PAG PAG 102 PAG 102 PAG 117 PAG 104PAG 118 PAG 110 DissInh — DISS 101 — — — DISS 102 Base BASE 101 BASE 101BASE 107 BASE 102 BASE 107 BASE 103 Solvent SOLV 101 SOLV 102 SOLV 101SOLV 101 SOLV 101 SOLV 103 Ratio (ppw) 11.5/0.3/ 13.0/0.3/ 14.5/0.7/14.0/0.4/ 13.7/0.3/ 13.2/0.8/ 0.0/0.04/ 2.1/0.05/ 0.0/0.03/ 0.0/0.02/0.0/0.03/ 2.2/0.03/ 84.7 85.8 86.0 85.1 85.5 84.4 Substrate Si BARC 101BARC 101 BARC 102 BARC 102 BARC 102 PB [° C./sec] 90/60 90/60 90/60110/60 135/60 135/60 FT [μm] 0.75 0.67 0.75 0.75 0.75 0.75 Exposure TypeKrF KrF KrF KrF KrF KrF Dose [mJ (μC)/cm²] 38 34 42 28 26 32 PEB [°C./sec] 105/90  115/90  105/90  120/90 135/90 135/90 Dev [° C./sec]23/60 23/60 23/60  23/60  23/60  23/60 Res [μm] 0.18 0.19 0.17 0.19 0.180.18 Delay Stability [hrs] >2 >2 >4 >2 >4 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] 1.20 1.30 1.20 1.25 1.301.25 EXAMPLE # 120 121 122 123 124 125 Polymer POLY 112 POLY 113 POLY114 POLY 114 POLY 115 POLY 116 PAG PAG 122 PAG 125 PAG 102 PAG 104 PAG126 PAG 123 DissInh — DISS 101 — — — DISS 102 Base BASE 107 BASE 107BASE 107 BASE 104 BASE 106 BASE 107 Solvent SOLV 101 SOLV 102 SOLV 101SOLV 101 SOLV 101 SOLV 101 Ratio 16.0/0.4/ 13.1/0.1/ 14.3/0.4/ 14.7/0.3/13.9/0.7/ 12.2/0.4/ 0.0/0.05/ 0.8/0.04/ 0.0/0.1/ 0.0/0.03/ 6.0/0.03/1.4/0.03/ 83.5 85.9 85.0 84.5 85.3 85.6 Substrate BARC 101 Si BARC 101BARC 103 BARC 105 BARC 101 PB [° C./sec] 90/60 110/60 90/60 110/60115/60 115/60 FT [μm] 0.75 0.67 0.55 0.75 0.52 0.70 Exposure Type KrFe-beam KrF KrF ArF KrF Dose [mJ (μC)/cm²] 38 26.4 47 28 14 52 PEB [°C./sec] 105/90  125/90 105/90  110/90 125/90 115/90 Dev [° C./sec] 23/60 23/60 23/60  23/60  23/20  23/60 Res [μm] 0.18 0.15 0.17 0.19 0.15 0.18Delay Stability [hrs] >2 >2 >4 >2 >1 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] 1.20 >1.30 1.20 1.25 1.301.25 EXAMPLE # 126 127 128 129 130 131 Polymer POLY 117 POLY 118 POLY118 POLY 115 POLY 119 POLY 120 PAG PAG 125/ PAG 102 PAG 101 PAG 124 PAG104 PAG 110 120 DissInh — — DISS 3 — — DISS 4 Base BASE 107 BASE 101BASE 105 BASE 103 BASE 102 BASE 104 Solvent SOLV 101 SOLV 102 SOLV 101SOLV 101 SOLV 101 SOLV 103 Ratio 14.3/0.8/ 16.5/0.4/ 16.1/0.1/ 14.3/0.4/14.7/0.4/ 17.9/0.5/ 0.0/0.1/ 0.0/0.04/ 0.8/0.04/ 0.0/0.1/ 0.0/0.03/0.0/0.03/ 87.0 83.5 85.9 85.0 84.5 85.3 Substrate Si BARC 104 BARC 101BARC 105 BARC 101 Si PB [° C./sec] 110/60 115/60 135/60 135/60 110/6090/60 FT [μm] 0.75 0.67 0.75 0.45 0.65 0.75 Exposure Type x-ray KrF KrFArF KrF i-line Dose [mJ (μC)/cm²] 65 34 42 19 46 78 PEB [° C./sec]125/90 125/90 135/90 135/90 120/90 100/90  Dev [° C./sec]  23/60  23/60 23/60  23/60  23/60 23/60 Res [μm] 0.12 0.17 0.19 0.15 0.18 0.24 DelayStability [hrs] >2 >2 >4 >2 >4 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] >1.80 1.30 1.20 1.45 1.300.25 EXAMPLE # 132 133 134 135 136 137 Polymer POLY 110 POLY 116 POLY121 POLY 111 POLY 111 POLY 120 PAG PAG 102 PAG 126 PAG 124 PAG 119 PAG102 PAG 110 DissInh — DISS 101 — — — DISS 102 Base BASE 101 BASE 101BASE 103 BASE 102 BASE 103 BASE 104 Solvent SOLV 101 SOLV 102 SOLV 101SOLV 101 SOLV 101 SOLV 103 Ratio 16.3/0.41 16.2/0.7/ 15.8/0.1/ 14.3/0.4114.7/0.4/ 17.9/0.51 0.0/0.1/ 0.0/0.02/ 0.8/0.04/ 0.0/0.1/ 0.01/0.03/0.0/0.03/ 85.3 83.5 85.9 85.0 84.5 85.3 Substrate BARC 101 Si BARC 105BARC 102 BARC 101 Si PB [° C./sec] 90/60 90/60 125/60 110/60 135/6695/60 FT [μm] 0.77 0.67 0.45 0.57 0.68 0.85 Exposure Type KrF x-ray ArFKrF KrF i-line Dose [mJ (μC)/cm²] 38 54 12 28 26 96 PEB [° C./sec]105/90  115/90  115/90 120/90 135/90 100/90  Dev [° C./sec] 23/60 23/60 23/60  23/60  23/60 23/60 Res [μm] 0.20 0.15 0.14 0.19 0.18 0.26 DelayStability [hrs] >2 >2 >1 >2 >4 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] 1.05 >1.80 1.40 1.25 1.35—

The following abbreviations were used for the ingredients shown in thetable.

POLY 101 to POLY 109=see the above examples

POLY 110=poly-(4-hydroxystyrene-co-4-(1-ethoxyethoxy)styrene), 6.7:3.3;Mw=8,700; D=1.12;

POLY 111=poly-(4-hydroxystryene-co-t-butylmethacrylate); 7.2:2.8;Mw=11,400; D=1.86;

POLY 112=poly-(4-hydroxystyrene-co-4-(1-ethoxyisopropoxy)styrene;6.9:3.1; Mw=8,200; D=1.14;

POLY 113=poly-(3-hydroxystyrene-co-4-t-butyl vinylphenoxyacetate);6.8:3.2; Mw=15,200, D=2.21;

POLY114=poly-(4-hydroxystyrene-co-4-(1-ethoxyethoxy)styrene-co-4-methylstyrene);6.0:3.2 0.8; Mw=14,000; D=1.84;

POLY115=poly-(4-hydroxystyrene-co-8-methyl-8-t-butoxycarbonyltetracyclo[4.4.0.1^(2.5).1^(7.10)]dodec-3-ene-co-maleicanhydride); 1:4:5; Mw=4,800; D=2.45;

POLY116=poly-(4-hydroxystyrene-co-4-(1-ethoxyethoxy)styrene-co-4-tetrahydropyranyloxystyrene);6.5:2.5:1.0; Mw=9,400; D=1.18;

POLY 117=poly-(4-hydroxystyrene-co-styrene-co-4-t-butylvinylphenoxyacetate); 6.0:2.0:2.0; Mw=12,300; D=1.72;

POLY118=poly-(4-hydroxystyrene-co-4-t-butyloxycarbonyloxystyrene-co-t-butylmethacrylate);6.8:2.1:1.1; Mw=7,200, D=1.65;

POLY119=poly-(-4-hydroxystyrene-co-4-butoxystyrene-co-4-(1-ethoxyethoxy)styrene-co-4-vinylbenoicacid t-butylester); 7.0:1.2:1.3:0.5; Mw=11,300, D=2.25;

POLY 120=poly-(4-hydroxystyrene-co-2-hydroxystyrene); 2:8; Mw=9,200,D=1.85;

POLY 121=poly-(2-hydroxystyrene-co-2-methyl-adamantylmethacrylate-co-mevalonyl methacrylate); 1:6:3; Mw=7,700, D=2.17;

PAG 101 to PAG 126=see the above synthesis examples DISS101=4,4′-(1-phenylethylidene)-bis-[4,1-phenyleneoxy aceticacid]-di-(1,1-dimethylethyl)ester,

DISS 102=ethylidene tris-[4,1-phenyleneoxy aceticacid]-tris-(1,1-dimethylethyl)ester,

DISS103=(1-methylethylidene)-di-4,1-phenylene-bis-(1,1-dimethylethyl)carbonicacid ester,

DISS 104=ethylidene-tris-4,1-phenylene-tris-(1,1-dimethylethyl)carbonicacid ester,

BASE 101=tetramethyl ammonium hydroxide,

BASE 102=tetra-n-butyl ammonium hydroxide,

BASE 103=tetra-n-butyl ammonium lactate,

BASE 104=methyldicyclohexylamine,

BASE 105=tri-n-octylamine,

BASE 106=triethanolamine,

BASE 107=triphenyl sulfonium acetate,

SOLV 101=propylene glycol monomethyl ether acetate,

SOLV 102=ethyl lactate,

SOLV 103=methyl amyl ketone,

BARC 101=DUV BARC AZ® KrF-3B® (available from Clariant Japan K.K.),

BARC 102=DUV BARC CD-9® (available from Brewer Science),

BARC 103 DUV BARC DUV18® (available from Brewer Science)

BARC 104 DUV BARC DUV42® (available from Brewer Science),

BARC 105=i-line BARC AZ® BarLi® II (available from Clariant Japan K.K.).

All formulations contain a minor amount(<0.01 ppw) of Megafac R-08(tradename) surfactant.

Example 138 and Comparative Examples 105 and 106

The following ingredients were mixed together to prepare three solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure:

9.8 g of the terpolymer (POLY 102) of the Example 102,

0.35 g (0.708 mmol) of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (Example 138) or

0.54 g (0.708 mmol) of triphenyl sulfonium perfluorooctane sulfonate(Comparative Example 104) or

0.29 g (0.708 mmol) of triphenyl sulfonium trifluoromethane sulfonate(Comparative Example 105),

0.02 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solutions were filtered, and spin coated on two silicon wafers each,which have been precoated with DUV 30, an antireflective coatingprovided by Brewer Science at a film thickness of 90 nm (bakeconditions: 190° C./60 sec). The substrate reflectivity at this filmthickness was approximately 6%. The films were baked for 90 seconds at120° C. to yield thin films having a thickness of 0.72±0.01 μm andexposed as described in Example 101. The exposure was followed by a postexposure bake at 120° C. for 60 seconds and a development.

The following results (Table 104) were obtained. The test items in thetable were the same as those in Example 103.

TABLE 104 Comparative Comparative Example 138 Example 105 Example 106Dose (mJ/cm²) 22 (2) 26 (3) 21 (1) Dense Line 0.22 (1) 0.24 (3) 0.22 (1)Resolution (μm) Isolated Line 0.12 (1) 0.15 (3) 0.13 (2) Resolution (μm)Dense Line DOF 0.5-0.6 (1) 0.0 (3) 0.3-0.4 (2) @ 0.22 μm (μm) IsolatedLine DOF 1.8 (1) 1.6 (3) 1.7-1.8 (2) @ 0.22 μm (μm) Dense/iso bias 22(1) Na (3) 27 (2) @ 0.22 μm (nm) Dense Pattern Good (2) Very good (1)Good (2) Profile @ 0.18 μm Isolated Pattern Good (1) Film Loss (3)Tapered (2) Profile @ 0.15 μm Standing Waves Visible (1) Strong (2)Visible (1) Dense/iso bias 22 (1) Na (3) 27 (2) @ 0.22 μm (nm)

From these results, it can be concluded that the material of the presentinvention has some superiority in the overall performance.

Example 139 and Comparative Examples 107 and 108

The following ingredients were mixed together to prepare three solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure.

9.8 g of the terpolymer (POLY 103) of Example 103,

0.5 g of α, α-bis(cyclohexylsulfonyl)diazomethane,

0.35 g of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate(Example 139) or

0.35 g of triphenyl sulfonium trifluoromethane sulfonate (ComparativeExample 107) or

0.35 g of diphenyl iodonium trifluoromethane sulfonate (ComparativeExample 108),

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solutions were filtered, and spin coated on two silicon wafers each,which have been precoated with DUV 42, a antireflective coating providedby Brewer Science Corp., USA, at a film thickness of 60 nm (bakeconditions: 200° C./60 sec). The substrate reflectivity at this filmthickness was less than 5%. Baking for 90 seconds at 90° C. provided athin layer having a thickness of 0.65±0.01 μm. Top-view inspection ofthe photoresists by microscope and scanning electron microscopeindicated that all three films exhibited smooth surfaces without anysign of pinholes, popcorns, or cracking. The recording materials wereexposed as described in Example 101 (NA=0.55, σ=0.55) using a half-tonemask with 0.3 μm contact hole patterns at a dose of 18 mJ/cm², baked at105° C. for 90 seconds and developed.

The results are summarized in Table 105.

The test items were the same as those in Example 103.

TABLE 105 Comparative Comparative Example 139 Example 107 Example 108Dose (mJ/cm²) 42 (3) 41 (2) 32 (1) Dense C/H 0.22 (1) 0.22 (1) 0.22 (1)Resolution (μm) Isolated C/H 0.22 (1) 0.23 (2) 0.23 (2) Resolution (μm)Dense C/H DOF 1.8 (1) 1.7 (2) 1.6 (3) @ 0.25 μm (μm) Isolated C/H DOF @1.3 (1) 1.1 (3) 1.2 (2) 0.25 μm (μm) C/H Sidewalls Vertical (1) Vertical(1) Tapered (2) @ 0.25 μm C/H Bottom Good (1) Foot (2) Undercut (3) @0.25 μm C/H Top @ 0.25 μm Clear (1) Round (3) Round (2) Standing WavesVisible (1) Visible (1) Visible (1) Surface After Smooth (1) Popcorn (2)Popcorn (2) Development

These results indicate the material of the present invention aresuperior in performance also in use as contact hole resist.

Example 140 and Comparative Example 109

Monodisperse poly-(4-hydroxystyrene) (provided from Nippon Soda Corp.)was reacted with ethyl vinyl ether to prepare a copolymer. The copolymerhad a molecular weight of 6,800 with 32% of the phenolic hydroxy groupsprotected.

The following ingredients were mixed together to prepare two solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure.

9.8 g of the above polymer,

1.2 g of a divinyl ether derivative prepared by the Williamson etherreaction of 1 mol bisphenol A with 2 moles 2-chloroethyl vinyl ether,

0.35 g (0.708 mmol) of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (Example 140) or

0.29 g (0.708 mmol) of triphenyl sulfonium triflouromethane sulfonate(Comparative Example 109) or

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solutions thus obtained were filtered and spin coated on two siliconwafers each, which have been precoated with AZ KrF-2 (tradename), anantireflective coating provided by Clariant Japan K.K., at a filmthickness of 60 nm (bake conditions: 220° C./60 sec). The photoresistfilms were baked for 90 seconds at 115° C. to yield a film thickness of0.62±0.01 μm. After exposure as described in Example 101 (NA=0.55,σ=0.55) at a dose of 29 mJ/cm², the exposed wafers were baked at 120° C.for 90 seconds and developed.

The recording material of the present invention resolved lines andspaces down to 0.20 μm with vertical sidewalls profiles. The material ofthe Comparative Example 109 showed a resolution limit at 0.28 μm andstrong foot formation. A dissolution rate analysis revealed that thecontrast of the comparative material was significantly degraded probablydue to a crosslinking reaction of the divinyl ether derivative at theselected post exposure bake temperature.

Example 141

The following ingredients were mixed together to prepare a solution ofpositive-working chemically amplified radiation sensitive compositionsuitable for i-line (365 nm) exposure:

8.6 g of a copolymer (molecular weight 12,200) of3-methyl-4-hydroxystyrene and 4-hydroxystyrene (2:1),

2.8 g of the poly-N,O-acetal described in Example 138,

0.45 g of 2-anthryl diphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate,

0.04 g of triphenyl sulfonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

88.5 g of ethyl lactate.

The solution thus obtained was filtered and spin coated on a waferprecoated with a 160 nm thick film of AZ Barli (tradename), a commercialantireflective coating available from Clariant Japan K.K., which hasbeen baked at 200° C. for 60 seconds. The photoresist was baked at 110°C. for 60 seconds to give a film thickness of 850 nm. The coated waferwas exposed through a mask with line and space patterns down to 0.20 μmusing a Nikon SNR1705I stepper (NA=0.50) at a dose of 56 mJ/cm². Afterthe exposure, the wafer was baked at 90° C. for 60 seconds and developedas described in Example 101. After water rinsing, the wafer was driedand observed under SEM. The material resolved 0.26 μm lines and spacepatterns free of scum and T-top formation.

Example 142

A solution of a positive-working chemically amplified radiationsensitive composition suitable for VDUV (193 nm) exposure was preparedfrom the following ingredients:

11.14 g of poly(2-hydroxystyrene-co-2-methyl-2-adamantylmethacrylate-co-mevalonic lactone methacrylate) with a molecular weightof 8,000 and a polydisersity of 1.82,

0.31 g of bis-4-cyclohexylphenyl iodonium 3,3,3,2,1,1-hexafluoropropanesulfonate,

0.04 g of methyl diethanolamine,

0.004 g of Megafac R-08 (tradename), and

88.5 g of ethyl lactate.

The solution thus obtained was filtered and spin coated on a waferprecoated with a 60 nm thick film of an experimental methacrylate basedantireflective coating developed by Clariant Japan K.K., which has beenbaked at 200° C. for 60 seconds. The photoresist was baked at 90° C. for60 seconds to give a film thickness of 450 nm and exposed through a maskwith line and space patterns down to 0.10 μm using a ISI ArF excimerlaser with a NA=0.60 at a dose of 14.5 mJ/cm². After the exposure, thewafer was baked at 110° C. for 60 seconds and developed with an aqueousdeveloper AZ MIF 300 (tradename: available from Clariant Japan K.K.)containing 2.38% tetramethyl ammonium hydroxide for 60 seconds at 230°C. The material resolved 0.14 μm lines and space pattern without anyT-top formation. The interface between the antireflective coating andthe photoresist was free of scum.

Example 143

A solution of negative-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure was prepared from thefollowing ingredients:

7.9 g of a copolymer of 4-hydroxystyrene and styrene prepared by radicalpolymerization in the presence of2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) as a polymerizationinitiator, the copolymer having a molecular weight of 9,200 and apolydispersity of 2.14 as determined by GPC using polystyrene as thestandard and a monomer ratio of 8:2 as determined by ¹H-NMR,

2.0 g of distilled hexamethoxymethyl melamine,

0.3 g of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate,

0.02 g of tetrabutyl ammonium lactate,

0.004 g of Megafac R-08 (tradename), and

62.4 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered, spin coated onto a HMDS treatedsilicon wafer at 3,000 rpm, and baked on a hot plate at 115° C. for 60seconds. The resulting film thickness was 0.72 μm. An exposure asdescribed in Example 101 followed at a dose of 28 mJ/cm². The exposedmaterial was then subjected to a post exposure bake on a hot plate at125° C. for 90 seconds and developed. The fine lines and spaces wereresolved down to 0.20 μm. Isolated lines were resolved down to 0.16 μmwhen a dose of 34 mJ/cm² was applied. The depth-of-focus of the 0.16 μmlines was about 0.80 μm.

Examples 144 and 145

A solution of negative-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) and e-beam exposure was preparedfrom the following ingredients:

7.9 g of a copolymer of 4-hydroxystyrene and 4-methoxystyrene preparedby radical polymerization in the presence of2,2′-azobis(isobutyronitrile) as a polymerization initiator, thecopoylmer having a molecular weight of 9,600 and a polydispersity of2.21 as determined by GPC using polystyrene as the standard and amonomer ratio of 7.8:2.2 as determined by ¹H-NMR,

2.0 g of recrystallized tetramethoxymethyl glucoril,

0.5 g of tetrabutoxymethyl glucoril,

0.3 g of tris-(4-t-butylphenyl) sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

62.4 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered and spin coated onto two siliconwafers treated with an adhesion promoter (hexamethyl disilazane) at3,000 rpm. After baking on a hot plate at 95° C. for 60 seconds, a filmthickness of 0.74±0.2 μm was obtained. One wafer was subjected to anexposure through a mask with fine lines and space patterns down to 0.10μm using a Nikon NSR 2005 EX 10B KrF excimer laser stepper (NA=0.55,σ=0.80) at a dose of 24 mJ/cm². The other wafer was exposed with e-beamusing the e-beam writer described in Example 108 at a dose of 14.3μC/cm². The exposed materials then were subjected to a post exposurebake on a hot plate at 95° C. for 90 seconds and developed.

The excimer laser exposed material resolved fine lines and spaces downto 0.20 μm. Isolated lines were resolved down to 0.15 μm when a dose of31 mJ/cm² was applied. The depth-of-focus of the 0.15 μm lines was about0.90 μm.

The e-beam exposed material yielded isolated lines with a linewidthbelow 0.10 μm.

Examples 146 and 147

A solution of a negative-working chemically amplified radiationsensitive composition suitable for DUV (248 nm) and x-ray exposure wasprepared from the following ingredients:

5.9 g of a terpolymer of 4-hydroxystyrene, styrene and N-hydroxymethylmethacrylamide with a molecular weight of 11, 500, a polydispersity of1.69, and a monomer ratio of 8:1.8:0.2,

1.5 g of recrystallized tetramethoxymethyl glucoril,

0.5 g of 4,4′-(1-methylethylidene)-bis-[2,6-bis-(hydroxymethyl)-phenol]

0.3 g of di-(4-t-butylphenyl) iodonium 3,3,3,2,1,1-hexafluoropropanesulfonate,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

62.4 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered and spin coated onto two siliconwafers treated with an adhesion promoter (hexamethyl disilazane) at3,000 rpm. After baking on a hot plate at 95° C. for 60 seconds, a filmthickness of 0.67±0.02 μm was obtained.

One of the wafers was subjected to an exposure through a mask with finelines and space patterns down to 0.10 μm using a Nikon NSR 2005 EX 10BKrF excimer laser stepper (NA=0.55, σ=0.55) at a dose of 18 mJ/cm². Theother wafer was exposed with x-rays as described in Example 110 at adose of 52 mJ/cm². The exposed materials were then subjected to a postexposure bake on a hot plate at 95° C. for 90 seconds and developed.

The fine lines and spaces of the excimer laser exposed material wereresolved down to 0.22 μm. Isolated lines were resolved down to 0.18 μmwhen a dose of 25 mJ/cm² was applied. The depth-of-focus of the 0.18 μmlines was about 1.25 μm.

The x-ray exposed material resolved dense lines and spaces down to 0.16μm while isolated lines were resolved down below 0.16 μm.

Example 148 and Comparative Example 110

Two negative-working chemically amplified radiation sensitivecomposition solutions suitable for i-line (365 nm) exposure wereprepared from the following ingredients:

7.2 g of a copolymer (molecular weight 15,000, glass transitiontemperature 145° C.) of 3,5-dimethyl-4-hydroxystyrene and4-hydroxystyrene (3:7),

2.0 g of distilled hexamethoxymethyl melamine,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

42.4 g of propylene glycol monomethyl ether acetate.

To one of the base formulations, a solution of 0.35 g of(4-phenyl-thiophenyl) diphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate dissolved in 20 g of propylene glycol monomethyl ether acetatewas added (Example 145),

while to the other base formulation,

0.35 g of (4-phenyl-thiophenyl) diphenyl sulfonium trifluoromethanesulfonate dissolved in 20 g of propylene glycol monomethyl ether acetatewas added (Comparative Example 110).

The solutions thus obtained were filtered and spin coated onto HMDStreated silicon wafers at 2,400 rpm. After baking on a hot plate at 90°C. for 60 seconds, both materials yielded a film thickness of 1.06±0.03μm.

The wafers were subjected to an exposure through a mask with fine linesand space patterns down to 0.20 μm using a Nikon NSR 1755i 7a i-linestepper at a dose of 82 mJ/cm². The exposed materials were then baked ona hot plate at 105° C. for 90 seconds and developed.

The material of the Example 145 resolved 0.28 μm lines and spacespatterns and the profile of the resist patterns were ideallyrectangular. No whisker-like raised portions or scum were observed. Thedose to print isolated lines with a width of 0.28 μm was found to be 91mJ/cm².

The material of the Comparative Example 110 also resolved 0.28 μm linesand spaces patterns. However, the top of the line patterns was rounded,and the bottom of the line patterns had an undercut structure combinedwith severe scum. The dose to print isolated lines with a width of 0.28μm was found to be 95 mJ/cm² and therefore this formulation was judgedto be clearly inferior to that of the Example 145.

Example 149 and Comparative Example 111

From Example 104, it is evident that the replacement of triflate basedPAGs with the hexaflate based PAGs of the present invention yieldsradiation sensitive compositions with identical sensitivity andresolution capability.

A quartz wafer (wafer 1) was coated with a solution containing a mixtureof

5.0 g of poly-(4-hydroxystyrene), and

0.3 g of triphenyl sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate(Example 149, wafer 1) dissolved in

50 g of propylene glycol monomethyl ether actetate and baked at 120° C.for 60 seconds.

A second quartz wafer (wafer 2) was coated with a solution containing amixture of

5.1 g poly-(4-hydroxystyrene), and

0.3 g triphenyl sulfonium triflate (Comparative Example 111, wafer 2)dissolved in

50 g propylene glycol monomethyl ether acetate and baked at 120° C. for60 seconds.

In addition, two other quartz wafers (wafer 3 and wafer 4) were coatedwith a solution of

5.0 g poly-(4-t-butyloxycarbonyloxystyrene) dissolved in

50 g propylene glycol monomethyl ether acetate and baked at 90° C. for90 seconds. Wafers 3 and 4 were subjected to a quantitative FIR spectrumanalysis with respect to the intensity of the carbonyl bond. Then thefilm of wafer 3 was brought into intimate contact with the film of wafer1 and the film of wafer 4 with the film of wafer 2 each at a pressure ofabout 0.05 kg/cm². Both wafer pairs were subjected to a floodirradiation with DUV KrF excimer laser irradiation at a dose of 80mJ/cm² and baked at 90° C. for 90 seconds with wafers 3 and 4 on theupper side. The wafers 3 and 4 were separated from wafers 1 and 2 andtheir FIR spectra were again recorded. After substraction of the twospectra (before and after exposure/bake), it became evident that 47% ofthe t-butyloxycarbonyloxy groups of the polymer on wafer 4 had beencleaved into hydroxy groups by trifluoromethanesulfonic acid producedduring exposure and diffusing into the polymer during the post exposurebake, while only 14% of the t-butyloxycarbonyloxy groups of the polymeron wafer 3 had been cleaved, indicating that the trifluoromethanesulfonic acid produced from wafer 2 was much more volatile than the3,3,3,2,1,1-hexafluoropropanesulfonic acid produced from wafer 1. Fromthis experiment, it can be concluded that the amount of acidic,corrosive and volatile products which might cause destruction of theirradiation equipment and pose hazards to the health of the workers issignificantly reduced, when triflate generating PAGs were replaced withthe PAGs of the present invention.

Example 150

The radiation sensitive composition of Example 141 was coated on amechanically surface grained aluminum foil and dried to a weight ofabout 1.2 g/m². After imagewise exposure through a positive-workingoriginal with a 5 kW metal halide light source for 23 seconds, the foilwas heated at 100° C. for 8 minutes in a convection oven. The printedimage was developed with a developer solution containing the followingingredients by a plush paddle method:

5.0 g of sodium lauryl sulfate,

1.5 g of sodium metasilicate pentahydrate,

1.6 g of trisodium phosphate dodecahydrate, and

92.5 g of ion-exchanged water.

The plate was then rinsed with pure water and dried. Step 6 of asilver-film continuous-tone step having a density range from 0.05 to3.05 and density increments of 0.15 was completely reproduced on thecopy. Even the finest screens and lines of the original were clearlyvisible. The printing plate obtained in the manner described gave 32,000high quality impressions on a sheetfed offset printing machine.

Example 151 and Comparative Example 112

Monodisperse poly-4-hydroxystyrene (Nippon Soda Co., Ltd., Mw=about9,000, polydispersity=1.08) was reacted with ethylene vinyl ether in thepresence of p-toluenesulfonic acid as a catalyst to prepare a copolymerof 4-hydroxystyrene and 4-(2-ethoxy)-ethoxystyrene. The copolymer had anaverage molecular weight of 10,500 as determined by GPC usingpolystyrene as the standard. The molar ratio of4-hydroxystyrene:4-(2-ethoxy)-ethoxystyrene was about 6.9:3.1 asmeasured by ¹H NMR. The following ingredients were mixed together toprepare two solutions of a positive-working chemically amplifiedradiation sensitive composition suitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.42 g of tris-4-t-butylphenyl sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (Example 51) or

0.36 g of triphenyl sulfonium triflate (Comparative Example 112),

0.03 g of triethanolamine,

0.05 g of N,N-dimethylacetamide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solutions thus obtained were filtered and spin coated on siliconcovered with a phosphor-spin-on-glass (PSG) layer, which has beenpretreated by a dehydration bake at 150° C., and baked on a hot plate at95° C. for 90 seconds to yield a thin layer having a thickness of about0.65 μm. The recording material was exposed as described in Example 101(NA=0.55, σ=0.71) using a mask with contact hole patterns down to 0.15μm at a dose of 52 mJ/cm² and baked for 90 seconds at 115° C. Next thematerial was developed as described in Example 101.

SEM inspection revealed that the recording material of the presentinvention resolved 0.18 μm contact holes at a duty ratio of 1:1 with adepth-of-focus (DOF) of about 1.40 μm. The side walls of the contactholes were vertical, and virtually no footing was observed at theresist/substrate interface. The comparative material resolved 0.20 μmcontact holes with a depth-of-focus (DOF) of less than 0.8 μm.

Example 152 and Comparative Example 113

The following ingredients were mixed together to prepare two solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure:

9.8 g of the above terpolymer (POLY 102),

0.4 g of tris-(4-t-butylphenyl)sulfonium 3,3,3,2,1,1-hexafluoropropanesulfonate (Example 152) or

0.35 g of triphenyl sulfonium triflate (Comparative Example 113),

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered, spin-coated on a HMDS treatedsilicon wafer and baked for 60 seconds on a hot plate at 135° C. toyield a thin layer having a thickness of about 0.82 μm. The recordingmaterial was exposed in the same manner as in Example 101. The dose was29 mJ/cm² at which 1:1 lines and spaces of 0.25 μm were provided. Thefilm was then baked at 135° C. for 90 seconds. For both the materials,subsequent development as described in Example 101 yielded resolved lineand space patterns below 0.21 μm. SEM revealed that, for the material ofthe present invention, the linewidth of isolated and dense lines wasalmost equal, i.e. the iso to dense bias was negligible, whereas, forthe comparative material, a large iso to dense bias existed in thelines. Further, for the material of the present invention, the isolatedlines were free from dropouts of the film and resolved own to 0.12 μm.On the other hand, for the comparative material, here were dropouts ofisolated lines of less than 0.14 μm from the substrate.

Synthesis Example 201 Preparation of diphenyl 4-t-butylphenyl sulfoniumnonafluorobutane sulfonate (PAG 201)

A column having a length of 55 cm and an inner diameter of 5 cm waspacked with 700 g of Amberlyst A-26 (tradename) dispersed in methanol inits chloride form. 3,000 ml of methanol was added to 3,000 ml of a 54%aqueous solution of tetramethyl ammonium hydroxide. This alkali solutionwas used to convert the chloride form of the Amberlyst ion-exchangeresin to its hydroxide form. The column was then washed with methanoluntil the solution withdrawn from the column became neutral.

39.93 g (0.1 mol) of diphenyl 4-t-butylphenyl sulfonium bromide wasdissolved in about 50 ml of methanol. The solution was passed throughthe column by elution with methanol at a rate of 30 ml/hour. The eluatewas monitored using a potentiometer and occasionally tested for theabsence of bromide ions using an aqueous silver nitrate solution. Next,the concentration of the hydroxyl group was determined by titration with0.1 N HCl. The yield of diphenyl 4-t-butylphenyl sulfonium hydroxide wasabout 100%. The solution was adjusted to 1.0 mmol/g diphenyl4-t-butylphenyl hydroxide.

With stirring, to 500 g (50 mmol) of the diphenyl 4-t-butylphenylhydroxide was added dropwise 15.01 g (50 mmol) of distillednonafluorobutane sulfonic acid diluted with 50 ml of methanol at roomtemperature. The mixture was stirred at room temperature for 24 hours.The solvent was removed by evaporation. The oil (30.9 g (about 100%))thus obtained was crystallized to give pure diphenyl 4-t-butylphenylsulfonium nonafluorobutane sulfonate. The purity was measured by HPLCand found to be >99%. ¹H-NMR (CDCl₃): 1.44 (s, 9H, 4-t-butyl), 7.62-7.71(m, 14H, aromatic) ppm.

Synthesis Example 202 Preparation of triphenyl sulfoniumnonafluorobutane sulfonate (PAG 202)

91.03 g (0.45 mol) of diphenyl sulfoxide was dissolved in 1300 ml ofbenzene in a 2-liter three-neck round-bottom flask equipped with astirrer, a thermometer, a dropping funnel, a condenser, and a nitrogeninlet. The mixture was cooled to 4° C. with vigorous stirring. Asolution of 189.0 g (0.90 mol) of trifluoroacetic anhydride and 135.1 g(0.45 mol) of nonafluorobutane sulfonic acid was added dropwise thereto,while the temperature was maintained under ice cooling. After completionof the addition, the mixture was stirred for 1 hour. The temperature wasreturned room temperature, followed by stirring for additional 15 hours.After standing overnight, two separate phases were formed. The upperphase was removed and discarded. The oily bottom phase of approximately500 ml volume was dropped into 2000 ml of diethyl ether, upon which asemi-crystalline deposit was formed. The ether was decanted, and theprecipitate was dissolved in a minimum amount of dichloromethane. Thesolution was added dropwise to 1000 ml of vigorously stirred diethylether to reprecipitate the product. After completion of the addition,stirring was continued for 2 hours. After the solid was separated fromdiethyl ether, this procedure was repeated once more to enhance thecrystallinity of the product. The mixture was filtered, and thesemi-crystals were collected yielding 173.7 g of crude sulfonium salt.The melting point of the crude sulfonium salt was 75-78° C. Depending onthe purity, the crystals can be either recrystallized from ethyl acetateor dissolved in the minimum amount of dichloromethane and purified bycolumn chromatography on silica gel using a 95:5dichloromethane-methanol mixture to perform purification. The firstfractions containing unreacted diphenyl sulfoxide were discarded. Aftercollection of the main fractions, the solvent was evaporated to leave139.1 g (yield 58.7%) of triphenyl nonafluorobutane sulfonate as whitecrystals (m.p. 83-85.5° C.).

¹H-NMR (CDCl₃): δ=7.71-7.83 (m, 15H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 203 Preparation of tris-(4-t-butylphenyl) sulfoniumnonafluorobutane sulfonate (PAG 203)

48.18 g (0.15 mol) of bis-(4-t-butylphenyl) sulfoxide (prepared fromdiphenyl sulfide and t-butyl bromide via FeCl₃ catalyzed alkylation andsubsequent oxidation with 2-chlorobenzoic acid) was dissolved in 400 mlof 4-t-butylbenzene in a 1-liter three-neck round-bottom flask equippedwith a stirrer, a thermometer, a dropping funnel, a condenser and anitrogen inlet. The mixture was cooled to 4° C. with vigorous stirring.A solution of 63.0 g (0.30 mol) of trifluoroacetic anhydride and 45.0 g(0.15 mol) of nonafluorobutane sulfonic acid was added dropwise thereto,while the temperature was maintained under ice cooling. After completionof the addition, the mixture was stirred for 1 hour. The temperature wasreturned to room temperature, followed by stirring for additional 15hours. After standing overnight, two separate phases were formed. Theupper phase was removed and discarded. The oily bottom phase ofapproximately 150 ml volume was diluted with 800 ml of diethyl ether,and washed twice with water and a sodium bicarbonate solution. Theorganic phase was dried over MgSO₄. After removal of the solvent, asemicrystalline solid was obtained. The semicrystalline solid wasrecrystallized from diethyl ether. Thus, 66.1 g (60.2%) of whitecrystals of tris-(4-t-butylphenyl) sulfonium nonafluorobutane sulfonate(m.p. 198-200° C.) was obtained.

¹H-NMR (CDCl₃): δ=1.36 (s, 27H), 7.81-7.88 (d, 12H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Examples 204 to 208

The following sulfonium salts were synthesized in substantially the samemanner as in the above synthesis examples.

Tris-(4-methylphenyl) sulfonium nonafluorobutane sulfonate (PAG 204)

¹H-NMR (CDCl₃): δ=2.42 (s, 9H), 7.37-7.47 (d, 12H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

4-Methylphenyl-diphenyl sulfonium nonafluorobutane sulfonate (PAG 205)

¹H-NMR (CDCl₃): δ=2.45 (s, 3H), 7.40-7.55 (d, 14H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Bis-(4-methylphenyl)phenyl sulfonium nonafluorobutane sulfonate (PAG206)

¹H-NMR (CDCl₃): δ=2.43 (s, 6H), 7.43-7.53 (d, 13H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Bis-(4-t-butylphenyl)-phenyl sulfonium nonafluorobutane sulfonate (PAG207)

¹H-NMR (CDCl₃): δ=1.48 (s, 18H), 7.67-8.12 (m, 13H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

4-Cyclohexylphenyl-diphenyl sulfonium nonafluorobutane sulfonate (PAG208)

¹H-NMR (CDCl₃): δ=1.53-2.45 (m, 11H), 7.42-8.01 (m ,14H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 209 Preparation of tris-(4-butoxyphenyl) sulfoniumnonafluorobutane sulfonate (PAG 209)

To a stirred solution of 60.0 g (0.164 mol) of bis-(4-t-butoxyphenyl)sulfoxide in 26.8 g (0.34 mol) of pyridine and 400 ml of tetrahydrofuranwas dropped 126.57 g (0.34 mol) of trimethylsilyl nonafluorobutanesulfonate while keeping the temperature below −5° C. with a salted icebath. After completion of the addition, the reaction temperature wasraised to 5° C., followed by stirring for additional 20 minutes. AGrignard solution was prepared from 8.4 g (0.34 mol) of magnesium, 100 gof tetrahydrofuran and 68.6 g (0.38 mol) of 4-t-butoxy chlorobenzene,and added dropwise to the above solution at 0° C. The mixture wasstirred for 2 hours at this temperature. Then water was added todecompose the excess Grignard reagent, and the inorganic salts wereremoved by filtration. The solution was concentrated to about 160 ml andextracted with a mixture of 1200 ml of dichloromethane, 600 g of asaturated aqueous solution of ammonium chloride and 600 ml water. Theorganic phase was washed twice with water and dried. The solvent wasremoved to yield an oily product which was then purified by columnchromatography on silica gel using dichloromethane as the eluant. Thus,tris-(4-butoxyphenyl) sulfonium nonafluorobutane sulfonate was obtainedas a slightly yellowish powder. The structure was confirmed by ¹H-NMR(CDCl₃) with δ=1.42 (s, 27H), 7.35-7.42 (d, 6H) and 7.78-7.93 ppm (d,6H).

Synthesis Example 210 Preparation oftris-(4-t-butoxycarbonylmethoxyphenyl) sulfonium nonafluorobutanesulfonate (PAG 210)

A solution of 62.2 g (0.08 mol) of tris-(4-butoxyphenyl) sulfoniumnonafluorobutane sulfonate and 2.40 g (0.008 mol) of nonafluorobutanesulfonic acid in 200 ml of ethanol was refluxed for 8 hours withstirring. After evaporation of the solvent, the crude product oftris-(4-hydroxyphenyl) sulfonium nonafluorobutane sulfonate (yield about100%) was dissolved in 160 g of N,N-dimethylformamide and reacted with55.4 g (0.40 mol) of anhydrous potassium carbonate and 60.3 g (0.40 mol)of t-butyl chloroacetate at 80° C. for 3 hours. The cooled reactionmixture was poured into 700 ml of water and extracted withdichloromethane. The organic phase was washed with water and dried. Thesolvent was removed. The oily residue was purified by columnchromatography on silica gel using a dichloromethane and methanol as theeluent. The white product was collected to yield 34.4 g (yield 45%) ofanalytically pure tris-(4-t-butoxycarbonylmethoxyphenyl) sulfoniumnonafluorobutane sulfonate. The ¹H-NMR spectrum gave the followingsignals (CDCl₃): δ=1.45 (s, 27H), 4.76 (s, 6H), 7.15-7.18 (d, 6H).7.74-7.87 (d, 6H).

Synthesis Example 211 Preparation of β-oxocyclohexyl 2-norbornylmethylsulfonium nonafluorobutane sulfonate (PAG 211)

To a solution of 14.14 g (0.106 mol) of 2-chlorocyclohexane in 100 ml ofethanol was added dropwise 50 ml of a 15% solution of methylmercaptanesodium salt. The mixture was stirred for 3 hours. Then 600 ml water wasadded, and the mixture was extracted with dichloromethane. The organicphase was dried, and the solvent was removed to yield crudeβ-oxocyclohexyl methyl sulfide, which was purified by distillation (b.p.45-47° C./0.3 mmHg).

2.0 g (15.6 mmol) of this product was dissolved in 10 ml of nitromethaneand added dropwise with 20 g (114 mmol) of 2-bromonorbornane and stirredat room temperature for 1 hour. After that, a solution of 2.28 g (15.6mmol) of silver nonafluorobutane sulfonate dissolved in 400 ml ofnitromethane was added dropwise to the reaction mixture and stirred forthree hours at room temperature. The silver bromide was removed byfiltration. The filtrate was concentrated to 50 ml, and then addeddropwise to 600 ml of diethyl ether. The precipitated solid wascollected, washed with ether and recrystallized from ethyl acetate. Theyield of β-oxocyclohexyl 2-norbornyl methyl sulfonium nonafluorobutanesulfonate was 1.88 g.

¹H-NMR (CDCl₃): δ=1.33-2.28 (m, 16H), 2.30-3.10 (m, 5H), 4.95-5.53 ppm(2m, 2H).

Synthesis Example 212 Preparation of bis-(4-cyclohexylphenyl) iodoniumnonafluorobutane sulfonate (PAG 212)

A 500 ml three-neck round bottom flask equipped with a stirrer, athermometer, a dropping funnel, a condenser, and a nitrogen inlet wascharged with 43 g (0.20 mol) of potassium iodate, 69.2 g (0.43 mol) ofcyclohexylbenzene and 43 ml acetic anhydride. The mixture was cooled to−5° C. A mixture of 43 ml of acetic anhydride and 30.1 ml concentratedsulfuric acid was added dropwise thereto with vigorous stirring. Duringthe addition, the reaction temperature was kept below 5° C. After theend of the addition, the temperature of the reaction solution wasreturned to room temperature over a period of 2 to 3 hours. Theresulting mixture was left for 48 hours and cooled to 5° C. 100 g of a1:1 ice/water mixture was added with stirring. During this operation,the temperature of the reaction solution was kept below 10° C.Precipitated crystals of potassium salts were removed by filtration, andthe precipitates were extracted twice with petroleum ether. To theremaining aqueous solution was added dropwise 45 g of ammonium bromidedissolved in 100 ml water with stirring. The precipitate ofbis-(4-cyclohexylbenzene)iodonium bromide was isolated by filtration,washed, and dried.

15.26 g (28.5 mmol) of the bromide was dissolved in 100 ml ofdichloromethane and 10.3 g (34.2 mmol) of nonafluorobutane sulfonic acidwas added. The mixture was stirred at reflux for 6 hours. Hydrogenbromide evolved. After cooling, the reaction mixture was washed twicewith a 2.5% aqueous solution of tetramethyl ammonium hydroxide and thendried. The solvent was then removed. The yellowish residue wasrecrystallized from an isopropanol/isopropyl ether mixture to give 12.2g (63%) of bis-(4-cyclohexylphenyl) iodonium nonafluorobutane sulfonate.

¹H-NMR (CDCl₃): δ=1.12-1.75 (m, 22H), 7.23-7.90 (d, 8H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Examples 213-215

The following iodonium salts were synthesized in substantially the samemanner as in the above synthesis examples. Diphenyl iodoniumnonafluorobutane sulfonate (PAG 213)

¹H-NMR (CDCl₃): δ=7.20-7.35 (m, 10H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Bis-(4-methylphenyl) iodonium nonafluorobutane sulfonate (PAG 214)

¹H-NMR (CDCl₃): δ=2.25 (s, 6H), 7.20-7.58 (d, 8H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Bis-(4-t-butylphenyl) iodonium nonafluorobutane sulfonate (PAG 215)

¹H-NMR (CDCl₃): δ=1.48 (s, 18H), 7.35-7.49 (d, 8H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Synthesis Example 216 Preparation of 4-methylphenyl phenyl iodoniumnonafluorobutane sulfonate (PAG 216)

To a stirred suspension of 4.40 g (20 mmol) of iodosylbenzene in 100 mlof dichloromethane was added dropwise 6.0 g (20 mmol) ofnonafluorobutane sulfonic acid at 0° C. under exclusion of moisture. Themixture was stirred at room temperature for 2 hours. The temperature wasreturned to 0° C. again. 1.84 g (20 mmol) of toluene was added dropwise.After the addition, stirring was continued at room temperature foradditional 1 hour. The solvent as evaporated. The oily residue wasdissolved in diethyl ether. The solution was cooled to obtain crystalsof 4-methylphenyl phenyl iodonium nonafluorobutane sulfonate. Thecrystals were washed with hexane. The yield was 6.7 g.

¹H-NMR (CDCl₃): δ=2.25 (s, 3H), 7.18-7.58 (m, 9H) ppm.

The purity was determined by HPLC analysis and found to be >97%.

Example 201

A copolymer of 4-hydroxystyrene and 4-t-butyloxycarbonylstyrene wasprepared by reacting monodisperse poly-4-hydroxystyrene withdi-t-butylcarbonate. The copolymer had a molecular weight of 8,700 witha polydispersity of 1.18 as determined by GPC using polystyrene as thestandard. The molar ratio of4-hydroxystyrene:4-t-butyloxycarbonylstyrene was 7:3 as concluded frominspection of the ¹H NMR spectrum (POLY 201). The following ingredientswere mixed together to prepare a solution of a positive-workingchemically amplified radiation sensitive composition suitable for DUV(248 nm) exposure:

9.8 g of the above copolymer,

0.3 g of tris(4-t-butylphenyl) sulfonium nonafluorobutane sulfonate,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered through a teflon filter having a pore diameterof 0.1 μm, spin coated on a silicon wafer pre-coated with DUV-18, anantireflective coating provided by Brewer Science at a film thickness of115 nm (bake temperature: 200° C.), at 3,000 revolutions and dried at90° C. for 60 seconds on a hot plate to remove the solvent. Thus, a 0.75μm-thick film was obtained. The recording material thus obtained wasimagewise exposed using a mask providing lines and spaces patterns downto 0.10 μm per image with a DUV stepper Nikon NSR 2005 EX 10B, having anumerical aperture (NA) of 0.55 during exposure and a coherence factor(σ) of 0.55 with a dose of 22 mJ/cm². The material was baked at 100° C.for 90 seconds to develop the latent image, and then processed at 23° C.by puddle development with AZ 300 MIF (tradename), a surfactant freedeveloper containing 2.38% by weight of tetramethyl ammonium hydroxideprovided by Clariant Japan K.K. A defect-free image of the mask withhigh edge stability was obtained, structures <0.25 μm being resolvedfaithfully to detail and the width ratio (linearity of the resist) ofnominally equal lines/space structures being virtually constant in therange between 1.00 μm and 0.25 μm. In 250 nm image, the difference inlinewidth between dense lines and isolated lines was not more than 5 nm,and the dense/iso bias was very small. The resist profile was almostvertical and very smooth, as neither line edge roughness nor standingwaves were observed.

Example 202

Radical copolymerization of 4-acetoxystyrene, styrene andt-butylmethacrylate was carried out in the presence of2,2-azo-bis-isobutyronitrile as a polymerization initiator, followed byhydrolysis of the acetate groups of the copolymer with an aqueousammonium acetate solution to prepare a terpolymer of 4-hydroxystyrene,styrene and t-butyl methacrylate. The terpolymer had a molecular weightof 14,200 with a polydispersity of 1.69 as determined by GPC usingpolystyrene as the standard, and the molar ratio of4-hydroxystyrene:styrene:t-butylmethacrylate was 7:2:1 as determined by¹H NMR (POLY 202). The following ingredients were mixed together toprepare a solution of a positive-working chemically amplified radiationsensitive composition suitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.3 g of bis-(4-t-butylphenyl) iodonium nonafluorobutane sulfonate,

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered, spin-coated on a HMDS treatedsilicon wafer and baked for 60 seconds on a hot plate at 130° C. toyield a film thickness of 0.82 μm. The recording material was exposed inthe same manner as in Example 201. The dose was 30 mJ/cm². The film wasthen baked at 130° C. for 90 seconds. Subsequent development asdescribed in Example 201 resolved line and space patterns below 0.22 μm.From scanning electron microscope (SEM) inspection, it was concludedthat the linewidth of isolated and dense lines was almost equal, i.e.the dense to iso bias was negligible. Isolated line patterns wereresolved down to 0.14 μm.

Example 203 and Comparative Examples 201 and 202

Radical polymerization of 4-t-butyloxystyrene was carried out in thepresence of 2,2-azo-bis-isobutyronitrile as a polymerization initiator,followed by partial hydrolysis of the t-butyloxy groups with aconcentrated aqueous hydrogen chloride solution to prepare4-hydroxystyrene with 12% of the t-butyloxy groups being left intact.This copolymer was then reacted with ethyl vinyl ether in the presenceof p-toluenesulfonic acid as a catalyst to prepare a terpolymer of4-hydroxystyrene, 4-(1-ethoxyethoxy)styrene and 4-t-butoxystyrene. Theterpolymer thus obtained had a molecular weight of 23,400 with apolydispersity of 2.14 as determined by GPC using polystyrene as thestandard, and the molar ratio of 4-hydroxystyrene styrene:t-butylmethacrylate was 6.7:2.2:1.1 as measured by ¹H NMR (POLY 203).

The following ingredients were mixed together to prepare solutions of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.3 g (0.41 mmol) of tris-(4-t-butylphenyl)sulfonium nonafluorobutanesulfonate (Example 203),

0.02 g of triphenyl sulfonium acetate,

0.05 g of 9-anthramethyl acetate (DUV absorber),

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

For comparison, positive-working chemically amplified radiationsensitive composition solutions were prepared in the same manner asdescribed just above, except that 0.27 g (0.41 mmol) oftris-(4-t-butylphenyl)sulfonium camphor sulfonate (Comparative Example201) or 0.24 g (0.41 mmol) of tris-(4-t-butylphenyl)sulfoniumphenylsulfonium trifluoromethane sulfonate (Comparative Example 202) wasused instead of 0.3 g (0.41 mmol) of tris-(4-t-butylphenyl)sulfoniumnonafluorobutane sulfonate.

The solutions were filtered, and spin-coated on three silicon wafers,which have been precoated with an experimental antireflective coatingprovided by Clariant Japan K.K. at a film thickness of 60 nm (baketemperature: 220° C.). The resist films were baked for 60 seconds on ahot plate at 90° C. to yield a film thickness of 0.75±0.02 μm.

The recording materials were exposed as described in Example 201(NA=0.50, σ=0.50) and then baked at 105° C. for 60 seconds. Developmentwas done as described in Example 201. The results were as follows.

TABLE 201 Comparative Comparative Example 203 Example 201 Example 202Dose (mJ/cm²) 22 (1) 31 (3) 22 (1) Dense Line Resolution 0.17 (1) 0.26(3) 0.18 (1) (μm) Isolated Line 0.15 (1) 0.19 (2) 0.20 (3) Resolution(μm) Dense Line DOF @ 0.22 μm 1.4 (1) 0.0 (3) 1.1 (2) (μm) Isolated LineDOF @ 1.0 (1) 0.6 (3) 0.7-0.8 (2) 0.22 μm (μm) Dense/iso bias @ 0.22 9(1) Na (3) 27 (2) μm (μm)

Remarks

In the table, rating was added in parenthesis (1)=best,(2)=intermediate, (3)=poor.

The dose is defined as the exposure energy to delineate equal lines andspaces of 0.22 μm pattern width.

The dense line resolution is defined as the smallest equal lines andspaces patterns fully reproduced at that dose.

The isolated line resolution is defined as the smallest isolated linepattern without top film loss of the line at that dose.

The dense line DOF is defined as the depth of focus of equal lines andspaces at that dose.

The isolated line DOF is defined as the depth of focus of isolated linesat that dose.

The dense/iso bias is defined as the linewidth difference between denselines and isolated lines at that dose.

These results clearly demonstrate that the material using the resistmaterial of the present invention has the best lithographic performanceamong these three samples.

Example 204 and Comparative Examples 203 and 204

Monodisperse poly-4-hydroxystyrene (Nippon Soda Co., Ltd., Mw=12,000,polydispersity=1.16) was reacted with 2-chloroethyl vinyl ether in thepresence of p-toluenesulfonic acid as a catalyst to prepare a copolymerof 4-hydroxystyrene and 4-(1-(2-chloroethoxy)ethoxy)styrene. Thecopolymer had a molecular weight of 13,700 with a polydispersity of 1.21as determined by GPC using polystyrene as the standard, and the monomerratio of 4-hydroxystyrene:4-(1-(2-chloroethoxy)ethoxy)styrene was7.1:2.9 as measured by ¹H NMR (POLY 204).

The following ingredients were mixed together to prepare three solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.25 g of tris-(4-t-butylphenyl) sulfonium nonafluorobutane sulfonate(Example 204),

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

For comparison, positive-working chemically amplified radiationsensitive composition solutions were prepared in the same manner asdescribed just above, except that 0.25 g oftris-(4-t-butylphenyl)sulfonium triflate (Comparative Example 203) or0.25 g of tris-(4-t-butylphenyl)sulfonium propane sulfonate (ComparativeExample 204) was used instead of 0.25 g of tris-(4-t-butylphenyl)sulfonium nonafluorobutane sulfonate. The solutions were filtered, spincoated on two HMDS treated silicon wafers each (total 6 wafers), bakedfor 90 seconds on a hot plate at 110° C. to yield a layer having athickness of 0.75±0.02 μm. The recording material was exposed asdescribed in Example 201 (NA=0.55, σ=0.55). The dose was as indicated inTable 202. While one of each wafer was placed immediately on a hot plateand baked for 90 seconds at 75° C. (Test A), the second wafers werestored in the clean room for 60 minutes and then baked under the sameconditions (Test B). Next, these wafers were developed as described inExample 201. The results are compiled in Table 202.

TABLE 202 Comparative Comparative Example 204 Example 203 Example 204Test A Dose (mJ/cm²) 24 (2) 22 (1) 37 (3) Dense Line Resolution 0.17 (1)0.17 (1) 0.21 (2) (μm) Isolated Line 0.15 (1) 0.15 (1) 0.19 (2)Resolution (μm) Dense Line DOF @ 0.22 μm 1.4-1.5 (1) 1.1 (2) 1.1 (2)(μm) Isolated Line DOF @ 1.0 (1) 0.6 (3) 0.7-0.8 (2) 0.22 μm (μm)Dense/iso bias @ 0.22 17 (1) 30 (3) 27 (2) μm (nm) T-top None (1) None(1) None (1) Test B (after one hour) Dose (mJ/cm²) 24 (1) 23 (2) 34 (3)Dense Line Resolution 0.17 (1) 0.18 (2) 0.22 (3) (μm) Isolated Line 0.15(1) 0.16 (2) 0.21 (3) Resolution (μm) Dense Line DOF @ 0.22 μm 1.4-1.5(1) 0.9 (2) 0.6 (3) (μm) Isolated Line DOF @ 1.0 (1) 0.4 (3) 0.6 (2)0.22 μm (μm) Dense/iso bias @ 0.22 15 (1) 37 (3) 32 (2) μm (nm) T-topNone (1) Yes, slight Yes, medium

Remarks

The definition of the test items is the same as given in Example 203.T-top indicates formation of an insoluble phase on top of the resist.

These results demonstrate superior performance of the resist material ofthe present invention (Test A) and superiority in dimensional stabilityupon delay time changes (Test B).

Example 205

Monodisperse poly-4-hydroxystyrene (manufactured by Nippon Soda Co.,Ltd., Mw=2,000, polydispersity=1.16) was reacted with dihydropyran and aminor amount of α, ω-triethylene glycol divinyl ether in the presence ofp-toluenesulfonic acid to prepare a copolymer of 4-hydroxystyrene and4-tetrahydropyranyloxystyrene partially crosslinked by α, ω-triethyleneglycol divinyl ether. The copolymer had an average molecular weight of7,500 with an essentially trimodal molecular weight distribution atabout 2,300, 4,600 and 7,000 and a minor amount of higher crosslinkedparts as determined by GPC with polystyrene as the standard, and themonomer ratio of 4-hydroxystyrene:4-tetrahydropyranyloxystyrene wasroughly 6.9:3.1 as measured by ¹H NMR (POLY 205).

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above copolymer,

0.42 g of t-butyloxycarbonylphenyl diphenyl sulfonium nonafluorobutanesulfonate,

0.03 g of tri-n-octylamine,

0.05 g of N,N-dimethylacetamide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered, spin coated on a silicon wafer covered with aphosphor-spin-on-glass layer, which has been pretreated bake at 150° C.,and baked for 90 seconds on a hot plate at 115° C. to yield a layerhaving a thickness of 0.65 μm. The recording material was exposed asdescribed in Example 201 (NA=0.55, σ=0.71) using a mask with contacthole patterns down to 0.15 μm at a dose of 62 mJ/cm²and baked for 90seconds at 120° C. Next the material was developed as described inExample 201. Scanning electron microscope (SEM) inspection revealed thatthe recording material resolved 0.19 μm contact holes at a duty ratio of1:1 with a usable depth-of-focus (DOF) of about 0.7 μm. The sidewalls ofthe contact holes were vertically, and virtually no footing was observedat the resist/substrate interface.

Example 206

Monodisperse poly-4-hydroxystyrene (manufactured by Nippon Soda Co.,Ltd., Mw=8,000, polydispersity=1.09) was reacted with ethyl vinyl etherin the presence of p-toluenesulfonic acid as a catalyst to prepare acopolymer. The copolymer was reacted with di-t-butylcarbonate in thepresence of triethylamine to prepare a terpolymer of 4-hydroxystyrene,4-(1-ethoxyethoxystyrene) and 4-(t-butyloxycarbonyloxystyrene). Theterpolymer had an average molecular weight of 10,200 with apolydispersity of 1.13 as determined by GPC using polystyrene as thestandard, and the monomer ratio of4-hydroxystyrene:4-(1-ethoxyethoxy)styrene:4-t-butyloxycarbonyloxystyrenewas 6.5:3.8:0.7 as measured by ¹H NMR (POLY 206).

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the above terpolymer,

0.35 g of bis-(4-cyclohexylphenyl) phenyl sulfonium nonafluorobutanesulfonate,

0.02 g of tetrabutyl ammonium hydroxide,

0.02 g of N,N-dicyclohexylamine,

0.004 g of Megafac R-08 (tradename), and

64.2 g of ethyl lactate.

The solution thus obtained was filtered, spin-coated on a HMDS treatedsilicon wafer and baked for 90 seconds on a hot plate at 100° C. toyield a layer having a thickness of 0.55 μm. The recording material wasexposed as described in Example 201 (NA=0.55, σ=0.71) using a mask withcontact hole patterns down to 0.15 μm at a dose of 55 mJ/cm² and bakedfor 90 seconds at 120° C. Next the material was developed as describedin Example 201. Exposure was performed as described in Example 201 usingNA=0.50 and a σ-value=0.60 at a dose of 26 mJ/cm². The material wasbaked for 90 seconds at 105° C., and developed with the surfactant-freedeveloper of Example 201 for 60 seconds at 23° C. followed by waterrinsing.

The material resolved dense lines and spaces patterns down to 0.18 μmand isolated lines down to 0.14 μm. The pattern shape was rectangularand no standing waves were observed. The DOF of the isolated patternswas larger than 1.0 μm for 0.18 μm features.

Examples 207 and 208

Radical copolymerization of 4-acetoxystyrene with 4-t-butylacrylate wascarried out in the presence of2,2′-azobis-(4-dimethoxy-2,4-dimethylvaleronitrile) as a polymerizationinitiator, followed by hydrolysis of the acetate groups with an aqueousammonium acetate solution. A part of the hydroxy groups in the copolymerthus obtained were reacted with ethyl vinyl ether in the presence ofp-toluenesulfonic acid as a catalyst to prepare a terpolymer of4-hydroxystyrene, 4-(1-ethoxyethoxystyrene) and 4-t-butylacrylate. Theterpolymer had an average molecular weight of 8,700 with apolydispersity of 1.71 as determined by GPC using polystyrene as thestandard, and the molar ratio of4-hydroxystyrene:4-(1-ethoxyethoxy)styrene:4-t-butylacrylate was7.1:1.8:1.1 as measured by ¹H NMR (POLY 207). The following ingredientswere mixed together to prepare a solution of a positive-workingchemically amplified radiation sensitive composition suitable for DUV(248 nm) and e-beam exposure:

9.8 g of the above terpolymer,

0.28 g of bis-(4-cyclohexylphenyl) iodonium nonafluorobutane sulfonate,

0.03 g of triphenyl sulfonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered, spin-coated on two HMDS treated siliconwafers and baked on a hot plate for 90 seconds at 110° C. to yield alayer having a thickness of 0.53 μm. One of the recording materials wasexposed with excimer laser radiation provided by a Nikon NSR 2005 EX 10Bstepper with an NA=0.55 and a coherence factor σ=0.80 using a mask withlines and spaces patterns down to 0.10 μm at a dose of 22 mJ/cm². Theother recording material was pattern-wise exposed with e-beam radiationprovided from a JEOL JBXX 5DII operating at 50 keV with a spot size of10 nm (no proximity correction) at a dose of 16.2 μC/cm². The exposedwafers were placed on a hot plate and baked for 90 seconds at 120° C.The materials were then developed with AZ® MIF 300, a surfactant freedeveloper containing 2.38% by weight of tetramethyl ammonium hydroxideprovided by Clariant Japan K.K. for 60 seconds at 23° C. followed bypure water rinsing. The excimer laser exposed material resolved denselines and spaces patterns down to 0.18 μm and isolated lines and spacesdown to 0.14 μm. The pattern shape was rectangular and only minorstanding waves were observed. The DOF of the isolated patterns waslarger than 1.0 μm for 0.16 μm features.

The e-beam exposed material resolved dense lines and spaces down to 0.16μm and isolated lines down to 0.11 μm. The DOF of the isolated patternswas larger than 1.0 μm for 0.15 μm features.

Examples 209 and 210

A terpolymer of a 4-hydroxystyrene derivative, 4-(t-butoxystyrene) and4-t-butylcarbonylmethyloxy styrene was prepared by acid hydrolysis ofmonodisperse poly-4-t-butoxystyrene to leave 15% of the butoxy groupsintact. A part of the hydroxy groups in the copolymer were reacted witht-butyl bromoacetate in the presence of triethylamine as a catalyst. Theterpolymer had an average molecular weight of 8,700 with apolydispersity of 1.06 as determined by GPC using polystyrene as thestandard, and the molar ratio of4-hydroxystyrene:4-(t-butoxystyrene:4-t-butylcarbonyloxystrene was7.1:1.4:1.5 as measured by ¹H NMR (POLY 208).

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) and x-ray exposure:

9.8 g of the above terpolymer,

0.2 g of bis-(t-butylcarbonylmethyloxyphenyl) iodonium nonafluorobutanesulfonate,

0.15 g of tris-(t-butylcarbonylmethyloxyphenyl) sulfoniumnonafluorobutane sulfonate,

0.03 g of tributylammonium pyrovate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of methyl amyl ketone.

The solution was filtered, spin-coated on two HMDS treated siliconwafers and baked on a hot plate (90 sec/100° C.) to yield a layer havinga thickness of 0.72 μm. One of the recording materials was exposed withexcimer laser radiation provided by a Nikon NSR 2005 EX 10B stepper(NA=0.55, σ=0.55) using a mask with lines and spaces patterns down to0.10 μm at a dose of 25 mJ/cm². The other recording material waspatternwise exposed with x-ray radiation provided by a 0.6 GeVsuperconducting beam storage ring with a peak wavelength of 7.5 A usinga Karl Suss XRS-200/3 stepper with a proximity gap of 30 μm at a dose of70 mJ/cm². The x-ray mask had lines and spaces pattern down to 100 nmand was composed of 0.5 μm thick W-Ti absorber on a 2.0 μm thick SiCmembrane. The exposed wafers were baked for 90 seconds at 110° C. anddeveloped as described in Example 201.

The excimer laser exposed material resolved dense lines and spacespatterns down to 0.16 μm but the isolated lines were somewhat unstableand collapsed at geometries below 0.18 μm. The pattern shape wasrectangular and only minor standing waves were observed. The DOF of theisolated patterns was larger than 1.0 μm for 0.16 μm features.

The x-ray exposed material resolved dense lines and spaces down to 0.14μm and isolated lines down to 0.14 μm. At smaller geometries thepatterns tended to collapse. The DOF of the isolated patterns was largerthan 1.0 μm for 0.15 μm features.

Example 211

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure:

9.8 g of the terpolymer described in Example 207 (POLY 207),

0.8 g of 4,4′-(1-methylethylidene) bis-[4,1-phenyleneoxy acetic acid]di(1,1-dimethylethyl) ester,

0.2 g of bis-(4-cyclohexylphenyl) phenyl sulfonium nonafluorobutanesulfonate,

0.03 g of triphenyl sulfonium hydroxide,

0.05 g of a condensation product of 2 moles 9-anthrylmethanol reactedwith 1 mole toluene-1,3-diisocyanate (DUV absorber),

0.004 g of Megafac R-08 (tradename), and

64.2 g propylene glycol monomethyl ether acetate.

The solution was filtered, spin-coated on a HMDS treated silicon waferand baked on a hot plate (90 sec/100° C.) to yield a layer having athickness of 0.55 μm, exposed as described previously (NA=0.55) at adose of 35 mJ/cm², baked for 90 seconds at 120° C. and developed.

The material resolved dense lines and spaces patterns down to 0.16 μmand isolated lines down to 0.14 μm. The pattern shape was rectangularand only minor standing waves were observed. The DOF of the isolatedpatterns was about 0.6 μm for 0.16 μm features.

Examples 212 and 213

4-Hydroxystyrene, tetracyclododecyl methacrylate, t-butyl methacrylateand methacrylic acid 2-tetrahydropyranyl ester was radically polymerizedin the presence of 2,2′-azobis(isobutyronitrile) as a polymerizationinitiator to prepare a quaterpolymer. The quaterpolymer had an averagemolecular weight of 13,200 with a polydispersity of 2.4 as determined byGPC using polystyrene as the standard, and the monomer ratio of thecomponents was 1.5:3.5:2.5:2.5 as measured by ¹H NMR (POLY 209).

The following ingredients were mixed together to prepare a solution of apositive-working chemically amplified radiation sensitive compositionsuitable for DUV (248 nm) exposure and VDUV (193 nm) exposure:

7.8 g of the quaterpolymer described above,

2.8 g of 4,4′-(1-methylethylidene) bis-[4,1-cyclohexyleneoxy aceticacid] di(1,1-dimethylethyl) ester,

0.2 g of bis-(4-cyclohexylphenyl) iodonium nonafluorobutane sulfonate,

0.03 g of triethanolamine,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

The solution was filtered, spin-coated on two silicon wafers pretreatedwith AZ® KrF-2, a commercially available antireflective coatingavailable from Clariant Japan K.K, baked for 90 seconds at 120° C. toyield a layer having a thickness of 00.55±0.02 μm, and one wafer wasexposed as described in Example 201 (NA=0.55, σ=0.80) at a dose of 26mJ/cm², while the other wafer was exposed with an ISI ArF stepper with aNA=0.60 and a σ=0.75 at a dose of 12.5 mJ/cm². The exposed wafers werebaked for 90 seconds at 125° C. and developed.

The KrF excimer laser exposed material resolved dense lines and spacespatterns below 0.16 μm, isolated lines down to 0.14 μm, but both with aslight tendency to form T-tops. The ArF excimer laser exposed materialshowed the same resolution and pattern characteristics as the KrFexcimer laser exposed material, however, the DOF of 0.18 μm linesexceeded that of the KrF exposed material by 25%.

Examples 214-237

The following radiation sensitive compositions were prepared andprocessed according to the steps indicated in Table 203, where

“Polymer” denotes the polymer used,

“PAG” denotes the PAG (photoacid generator) used,

“DissInh” denotes the dissolution inhibitor used,

“Base” denotes the basic additive used,

“Solv” denotes the solvent used,

“Ratio” denotes the component ratio in parts by weight used,

“Substrate” denotes the substrate to be coated with the radiationsensitive composition used,

“PB” denotes the applied prebake conditions (temperature/time),

“FT” denotes the film thickness of the radiation sensitive compositionused,

“Exposure Type” denotes the radiation wavelength employed (ArF=193 nmexcimer laser, KrF=248 nm excimer laser, i-line=365 nm quartz lamp,e-beam=30 keV electron beams, x-ray=1.3 nm),

“Dose” denotes the applied exposure dose (in mJ/cm² for ArF. KrF, I-lineand x-rays and in μC/cm² for e-beam),

PEB denotes the applied post exposure bake conditions(temperature/time),

“Dev” denotes conditions for development (temperature/time) with anaqueous 2.38% tetramethyl ammonium hydroxide solution,

“Res” denotes the resolution capability of dense 1:1 lines and spaces,

“Delay Stability” denotes the linewidth change <10% upon delay betweenexposure and post exposure bake,

“Profile Angle” denotes the angle between the substrate and the sidewallof 0.25 μm line patterns, and

“DOF” denotes the depth of focus of 0.25 μm lines.

TABLE 203 EXAMPLE # 214 215 216 217 218 219 Polymer POLY 210 POLY 210POLY 210 POLY 211 POLY 211 POLY 211 PAG PAG 202 PAG 202 PAG 217 PAG 204PAG 218 PAG 210 DissInh — DISS 201 — — — DISS 202 Base BASE 201 BASE 201BASE 207 BASE 202 BASE 207 BASE 203 Solvent SOLV 201 SOLV 292 SOLV 201SOLV 201 SOLV 201 SOLV 203 Ratio (ppw) 11.5/0.3/ 13.0/0.3/ 14.5/0.7/14.0/0.4/ 13.7/0.31 13.2/0.8/ 0.0/0.04/ 2.11/0.05/ 0.0/0.03/ 0.0/0.02/0.01/0.03/ 2.2/0.03/ 84.7 85.8 86.0 85.1 85.5 84.4 Substrate Si BARC 201BARC 201 BARC 202 BARC 202 BARC 202 PB [° C./sec] 90/60 90/60 90/60110/60 135/60 135/60 FT [μm] 0.75 0.67 0.75 0.75 0.75 0.75 Exposure TypeKrF KrF KrF KrF KrF KrF Dose [mJ/cm²] 39 35 40 29 27 35 PEB [° C./sec]105/90  115/90  105/90  120/90 135/90 135/90 Dev [° C./sec] 23/60 23/6023/60  23/60  23/60  23/60 Res [μm] 0.18 0.19 0.17 0.19 0.18 0.18 DelayStability [hrs] >3 >3 >4 >3 >4 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] 1.20 1.30 1.20 1.25 1.301.25 EXAMPLE # 220 221 222 223 224 225 Polymer POLY 212 POLY 213 POLY214 POLY 214 POLY 215 POLY 216 PAG PAG 222 PAG 225 PAG 202 PAG 204 PAG226 PAG 223 DissInh — DISS 201 — — — DISS 202 Base BASE 207 BASE 207BASE 207 BASE 204 BASE 206 BASE 207 Solvent SOLV 201 SOLV 202 SOLV 201SOLV 201 SOLV 201 SOLV 201 Ratio 16.0/0.4/ 13.1/0.1/ 14.3/0.41 14.7/0.3113.9/0.7/ 12.2/0.4/ 0.0/0.05/ 0.8/0.04/ 0.0/0.1/ 0.0/0.03/ 0.0/0.03/1.4/0.03/ 83.5 85.9 85.0 84.5 85.3 85.6 Substrate BARC 201 Si BARC 201BARC 203 BARC 205 BARC 201 PB [° C./sec] 90/60 110/60 90/60 110/60115/60 115/60 FT [μm] 0.75 0.67 0.55 0.75 0.52 0.70 Exposure Type KrFe-beam KrF KrF ArF KrF Dose [mJ (μC)/cm²] 40 18.2 42 31 12 53 PEB [°C./sec] 105/90  125/90 105/90  110/90 125/90 115/90 Dev [° C./sec] 23/60 23/60 23/60  23/60  23/20  23/60 Res [μm] 0.18 0.15 0.17 0.19 0.15 0.18Delay Stability [hrs] >3 >3 >4 >3 >1 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] 1.20 >1.30 1.20 1.25 1.301.25 EXAMPLE # 226 227 228 229 230 231 Polymer POLY 217 POLY 218 POLY218 POLY 215 POLY 219 POLY 220 PAG PAG 225/ PAG 202 PAG 201 PAG 224 PAG204 PAG 210 220 DissInh — — DISS 203 — — DISS 204 Base BASE 207 BASE 201BASE 205 BASE 203 BASE 202 BASE 204 Solvent SOLV 201 SOLV 202 SOLV 201SOLV 201 SOLV 201 SOLV 203 Ratio 14.3/0.8/ 16.5/0.4/ 16.1/0.1/ 14.3/0.4/14.7/0.4/ 17.9/0.5/ 0.0/0.1/ 0.0/0.04/ 0.8/0.04/ 0.0/0.1/ 0.0/0.03/0.0/0.03/ 87.0 83.5 85.9 85.0 84.5 85.3 Substrate Si BARC 204 BARC 201BARC 205 BARC 201 Si PB [° C./sec] 110/60 115/60 135/60 135/60 110/6090/60 FT [μm] 0.75 0.67 0.75 0.45 0.65 0.75 Exposure Type x-ray KrF KrFArF KrF i-line Dose [mJ (μC)/cm²] 75 36 39 17 42 88 PEB [° C./sec]125/90 125/90 135/90 135/90 120/90 100/90  Dev [° C./sec]  23/60  23/60 23/60  23/60  23/60 23/60 Res [μm] 0.12 0.17 0.19 0.15 0.18 0.24 DelayStability [hrs] >3 >3 >4 >3 >4 >4 Profile Angle[°] >86 >87 >86 >86 >86 >86 DOF @ 0.25 μm [μm] >1.60 1.20 1.15 1.45 1.301.25 EXAMPLE # 232 233 234 235 236 237 Polymer POLY 210 POLY 216 POLY221 POLY 211 POLY 211 POLY 220 PAG PAG 202 PAG 226 PAG 224 PAG 219 PAG202 PAG 210 DissInh — DISS 201 — — — DISS 202 Base BASE 201 BASE 201BASE 203 BASE 202 BASE 203 BASE 204 Solvent SOLV 201 SOLV 202 SOLV 201SOLV 201 SOLV 201 SOLV 203 Ratio (ppw) 16.3/0.4/ 16.2/0.71 15.8/0.1/14.3/0.4/ 14.7/0.4/ 17.9/0.5/ 0.0/0.1/ 0.0/0.02/ 0.8/0.04/ 0.0/0.1/0.0/0.03/ 0.0/0.03/ 85.3 83.5 85.9 85.0 84.5 85.3 Substrate BARC 201 SiBARC 205 BARC 202 BARC 201 Si PB [° C./sec] 90/60 90/60 125/60 110/60135/60 95/60 FT [μm] 0.77 0.67 0.45 0.57 0.68 0.85 Exposure Type KrFx-ray ArF KrF KrF i-line Dose [mJ/cm²] 32 59 9 28 23 91 PEB [° C./sec]105/90  115/90  115/90 120/90 135/90 100/90  Dev [° C./sec] 23/60 23/60 23/60 23/60  23/60 23/60 Res [μm] 0.20 0.15 0.14 0.19 0.18 0.26 DelayStability [hrs] >3 >3 >2 >3 >4 >4 Profile Angle [°] >86 >87 >86 >86 >8686 DOF @ 0.25 μm [μm] 1.15 >1.60 1.30 1.25 1.35 —

The following abbreviations were used for the ingredients shown in thetable.

POLY 201 to POLY 209=see the above examples

POLY 210=poly-(4-hydroxystyrene-co-4-(1-ethoxyethoxy)styrene), 6.7:3.3;Mw=8,700; D=1.12;

POLY 211=poly-(4-hydroxystryene-co-t-butylmethacrylate); 7.2:2.8;Mw=11,400; D=1.86;

POLY 212=poly-(4-hydroxystyrene-co-4-(1-ethoxyisopropoxy)styrene;6.9:3.1; Mw=8,200; D=1.14;

POLY 213=poly-(3-hydroxystyrene-co-4-t-butyl vinylphenoxyacetate);6.8:3.2; Mw=15,200, D=2.21;

POLY214=poly-(4-hydroxystyrene-co-4-(1-ethoxyethoxy)styrene-co-4-methylstyrene);6.0:3.2 0.8; Mw=14,000; D=1.84;

POLY215=poly-(4-hydroxystyrene-co-8-methyl-8-t-butoxycarbonyltetracyclo[4.4.0.1^(2.5).1^(7.10)]dodec-3-ene-co-maleicanhydride); 1:4:5; Mw=4,800; D=2.45;

POLY216=poly-(4-hydroxystyrene-co-4-(1-ethoxyethoxy)styrene-co-4-tetrahydropyranyloxystyrene);6.5:2.5:1.0; Mw=9,400; D=1.18;

POLY 217=poly-(4-hydroxystyrene-co-styrene-co-4-t-butylvinylphenoxyacetate); 6.0:2.0:2.0; Mw=12,300; D=1.72;

POLY218=poly-(4-hydroxystyrene-co-4-t-butyloxycarbonyloxystyrene-co-t-butylmethacrylate);6.8:2.1:1.1; Mw=7,200, D=1.65;

POLY219=poly-(-4-hydroxystyrene-co-4-butoxystyrene-co-4-(1-ethoxyethoxy)styrene-co-4-vinylbenoicacid t-butylester); 7.0:1.2:1.3:0.5; Mw=11,300, D=2.25;

POLY 220=poly-(4-hydroxystyrene-co-2-hydroxystyrene); 2:8; Mw=9,200,D=1.85;

POLY 221=poly-(2-hydroxystyrene-co-2-methyl-adamantylmethacrylate-co-mevalonyl methacrylate); 1:6:3; Mw=7,700, D=2.17;

PAG 201 to PAG 216=see the above synthesis examples

PAG 217=bis-(4-butoxyphenyl diphenyl sulfonium nonafluorobutanesulfonate,

PAG 218=bis-(4-methylphenyl) phenyl sulfonium nonafluorobutanesulfonate,

PAG 219=tris-(4-chlorophenyl) sulfonium nonafluorobutane sulfonate,

PAG 220=tris-(t-butyloxycarbonyloxyphenyl) nonafluorobutane sulfonate,

PAG 221=phenyl dimethyl sulfonium nonafluorobutane sulfonate,

PAG 222=4-hydroxy-3,5-dimethylphenyl diphenyl sulfonium nonafluorobutanesulfonate,

PAG 223=2-naphthylcarbonylmethyl dimethyl nonafluorobutane sulfonate,

PAG 224=di-(4-t-butyloxyphenyl) iodonium nonafluorobutane sulfonate,

PAG 225=di-(4-t-butylcarbonylmethyloxyphenyl) nonafluorobutanesulfonate,

PAG 226=4-t-butylphenyl phenyl iodonium nonafluorobutane sulfonate,

DISS 201=4,4′-(1-phenylethylidene)-bis-[4,1-phenyleneoxy aceticacid]-di-(1,1-dimethylethyl)ester,

DISS 202=ethylidene tris-[4,1-phenyleneoxy aceticacid]-tris-(1,1-dimethylethyl)ester,

DISS203=(1-methylethylidene)-di-4,1-phenylene-bis-(1,1-dimethylethyl)carbonicacid ester,

DISS 204=ethylidene-tris-4,1-phenylene-tris-(1,1-dimethylethyl)carbonicacid ester,

BASE 201=tetramethyl ammonium hydroxide,

BASE 202=tetra-n-butyl ammonium hydroxide,

BASE 203=tetra-n-butyl ammonium lactate,

BASE 204=methyldicyclohexylamine,

BASE 205=tri-n-octylamine,

BASE 206=triethanolamine,

BASE 207=triphenyl sulfonium acetate,

SOLV 201=propylene glycol monomethyl ether acetate,

SOLV 202=ethyl lactate,

SOLV 203=methyl amyl ketone,

BARC 201=DUV BARC AZ® KrF-3B® (available from Clariant Japan K.K.),

BARC 202=DUV BARC CD-9® (available from Brewer Science),

BARC 203=DUV BARC DUV18® (available from Brewer Science),

BARC 204=DUV BARC DUV42® (available from Brewer Science),

BARC 205=i-line BARC AZ® BarLi® II (available from Clariant Japan K.K.).

All formulations contain a minor amount(<0.01 ppw) of Megafac R-08(tradename) surfactant.

Example 238 and Comparative Examples 205 and 206

The following ingredients were mixed together to prepare three solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure:

9.8 g of the terpolymer (POLY 202) of the Example 202,

0.52 g (0.708 mmol) of tris-(4-t-butylphenyl) sulfonium nonafluorobutanesulfonate (Example 238),

0.66 g (0.708 mmol) of tris-(4-t-butylphenyl) sulfonium perfluorooctanesulfonate (Comparative Example 205) or

0.41 g (0.708 mmol) of tris-(4-t-butylphenyl) sulfonium trifluoromethanesulfonate (Comparative Example 206),

0.02 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

For comparison, positive-working chemically amplified radiationsensitive composition solutions were prepared in the same manner asdescribed just above, except that 0.66 g (0.708 mmol) oftris-(4-t-butylphenyl)sulfonium perfluorooctane sulfonate (ComparativeExample 205) or 0.41 g (0.708 mmol) of tris-(4-t-butylphenyl)sulfoniumtrifluoromethane sulfonate (Comparative Example 206) was used instead of0.52 g (0.708 mmol) of tris-(4-t-butylphenyl) sulfonium nonafluorobutanesulfonate. The solutions were filtered, and spin coated on two siliconwafers each, which have been precoated with DUV 30, an antireflectivecoating provided by Brewer Science at a film thickness of 90 nm (bakeconditions: 190° C./60 sec). The substrate reflectivity at this filmthickness was approximately 6%. The films were baked for 90 seconds at120° C. to yield films having a thickness of 0.72±0.01 μm and exposed asdescribed in Example 201. The exposure was followed by a post exposurebake at 120° C. for 60 seconds and a development.

The following results (Table 204) were obtained.

TABLE 204 Comparative Comparative Example 238 Example 205 Example 206Dose (mJ/cm²) 25 (2) 33 (3) 24 (1) Dense Line 0.20 (1) 0.24 (3) 0.22 (1)Resolution (μm) Isolated Line 0.12 (1) 0.15 (3) 0.13 (2) Resolution (μm)Dense Line DOF 0.5-0.6 (1) 0.0 (3) 0.3-0.4 (2) @ 0.22 μm (μm) IsolatedLine DOF 1.8 (1) 1.6 (3) 1.7-1.8 (2) @ 0.22 μm (μm) Dense Pattern VeryGood (1) good (2) Good (2) Profile @ 0.18 μm Isolated Pattern Good (1)Film Loss (3) Tapered (2) Profile @ 0.15 μm Standing Waves Visible (2)Strong (2) Visible (1) Dense/iso bias 12 (1) Na (3) 23 (2) @ 0.22 μm(nm)

The test items in the table were the same as those in Table 203. Fromthese results, it can be concluded that the material of the presentinvention has some superiority in the overall performance.

Example 239 and Comparative Examples 207 and 208

The following ingredients were mixed together to prepare three solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure.

9.8 g of the terpolymer (POLY 203) of Example 203,

0.5 g of α, α-bis(cyclohexylsulfonyl)diazomethane,

0.52 g of tris-(4-t-butylphenyl) sulfonium nonafluorobutane sulfonate(Example 239),

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

For comparison, positive-working chemically amplified radiationsensitive composition solutions were prepared in the same manner asdescribed just above, except that 0.52 g oftris-(4-t-butylphenyl)sulfonium trifluoromethane sulfonate (ComparativeExample 207) or 0.52 g of bis-(4-t-butylphenyl)iodonium trifluoromethanesulfonate (Comparative Example 208) was used instead of 0.52 g oftris-(4-t-butylphenyl)sulfonium nonafluorobutane sulfonate.

The solutions were filtered, and spin coated on two silicon wafers each,which have been precoated with DUV 42, a antireflective coating providedby Brewer Science Corp., USA, at a film thickness of 60 nm (bakeconditions: 200° C./60 sec). The substrate reflectivity at this filmthickness was less than 5%. Baking for 90 seconds at 90° C. provided alayer having a thickness of 0.65±0.01 μm. Top-view inspection of thephotoresists by microscope and scanning electron microscope indicatedthat all three films exhibited smooth surfaces without any sign ofpinholes, popcorns, or cracking. The recording materials were exposed asdescribed in Example 201 (NA=0.55, σ=0.55) using a half-tone mask with0.3 μm contact hole patterns at the following dose, baked at 105° C. for90 seconds and developed.

The results are summarized in Table 205.

TABLE 205 Comparative Comparative Example 239 Example 207 Example 208Dose (mJ/cm²) 45 (3) 44 (2) 35 (1) Dense C/H 0.22 (1) 0.22 (1) 0.22 (1)Resolution (μm) Isolated C/H 0.22 (1) 0.23 (2) 0.23 (2) Resolution (μm)Dense C/H DOF 1.8 (1) 1.7 (2) 1.6 (3) @ 0.25 μm (μm) Isolated C/H DOF @1.3 (1) 1.1 (3) 1.2 (2) 0.25 μm (μm) C/H Sidewalls Vertical (1) Vertical(1) Tapered (2) @ 0.25 μm C/H Bottom Good (1) Foot (2) Undercut (3) @0.25 μm C/H Top @ 0.25 μm Clear (1) Round (3) Round (2) Standing WavesVisible (1) Visible (1) Visible (1) Surface After Smooth (1) Popcorn (2)Popcorn (2) Development

The test items were the same as those in Table 203. These resultsindicate the material of the present invention are superior inperformance also in use as contact hole resist.

Example 240 and Comparative Example 209

Monodisperse poly-(4-hydroxystyrene) (provided from Nippon Soda Corp.)was reacted with ethyl vinyl ether to prepare a copolymer. The copolymerhad a molecular weight of 6,800 with 32% of the phenolic hydroxy groupsprotected.

The following ingredients were mixed together to prepare two solutionsof a positive-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) exposure.

9.8 g of the above resin,

1.2 g of a divinyl ether derivative prepared by the Williamson etherreaction of 1 mol bisphenol A with 2 moles 2-chloroethyl vinyl ether,

0.52 g (0.708 mol) of tris-(4-t-butylphenyl) sulfonium nonafluorobutanesulfonate (Example 240),

0.03 g of triphenyl sulfonium acetate,

0.004 g of Megafac R-08 (tradename), and

64.2 g of propylene glycol monomethyl ether acetate.

For comparison, positive-working chemically amplified radiationsensitive composition solutions were prepared in the same manner asdescribed just above, except that 0.41 g (0.708 mmol) oftris-(4-t-butylphenyl)sulfonium trifluoromethane sulfonate (ComparativeExample 209) was used instead of 0.52 g (0.708 mmol) oftris-(4-t-butylphenyl)sulfonium nonafluorobutane sulfonate.

The solutions thus obtained were filtered and spin coated on two siliconwafers each, which have been precoated with AZ KrF-2 (tradename), anantireflective coating provided by Clariant Japan K.K., at a filmthickness of 60 nm (bake conditions: 220° C./60 sec). The photoresistfilms were baked for 90 seconds at 115° C. to yield a film thickness of0.62±0.01 μm. After exposure as described in Example 201 (NA=0.55,σ=0.55) at a dose of 32 mJ/cm², the exposed wafers were baked at 120° C.for 90 seconds and developed.

The recording material of the present invention resolved lines andspaces down to 0.20 μm with vertical sidewalls profiles. The material ofthe Comparative Example 209 showed a resolution limit at 0.28 μm andstrong foot formation. A dissolution rate analysis revealed that thecontrast of the comparative material was significantly degraded probablydue to a crosslinking reaction of the divinyl ether derivative at theselected post exposure bake temperature.

Example 241

The following ingredients were mixed together to prepare twopositive-working chemically amplified radiation sensitive compositionsolutions suitable for i-line (365 nm) exposure:

8.6 g of a copolymer (molecular weight 12,200) of3-methyl-4-hydroxystyrene and 4-hydroxystyrene (2:1),

2.8 g of the poly-N,O-acetal described in Example 238,

0.45 g of 2-anthryl diphenyl sulfonium nonafluorobutane sulfonate,

0.04 g of triphenyl sulfonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

88.5 g of ethyl lactate.

The solution thus obtained was filtered and spin coated on a waferprecoated with a 160 nm thick film of AZ Barli (tradename), a commercialantireflective coating available from Clariant Japan K.K., which hasbeen baked at 200° C. for 60 seconds. The photoresist was baked at 110°C. for 60 seconds to give a film thickness of 850 nm. The coated waferwas exposed through a mask with line and space patterns down to 0.20 μmusing a Nikon SNR1705I stepper (NA=0.50) at a dose of 56 mJ/cm². Afterthe exposure, the wafer was baked at 90° C. for 60 seconds and developedas described in Example 201. After pure water rinsing, the wafer wasdried and observed under SEM. The material resolved 0.26 μm lines andspace patterns free of scum and T-top formation.

Example 242

Two solutions of a positive-working chemically amplified radiationsensitive composition suitable for VDUV (193 nm) exposure were preparedby mixing the following ingredients together:

11.14 g of poly(2-hydroxystyrene-co-2-methyl-2-adamantylmethacrylate-co-mevalonic lactone methacrylate) with a molecular weightof 8,000 and a polydisersity of 1.82,

0.31 g of bis-4-cyclohexylphenyl iodonium nonafluorobutane sulfonate,

0.04 g of methyl diethanolamine,

0.004 g of Megafac R-08 (tradename), and

88.5 g of ethyl lactate.

The solution thus obtained was filtered and spin coated on a waferprecoated with a 60 nm thick film of an experimental methacrylate basedantireflective coating provided by Clariant Japan K.K., which has beenbaked at 200° C. for 60 seconds. The photoresist was baked at 90° C. for60 seconds to give a film thickness of 450 nm and exposed through a maskwith line and space patterns down to 0.10 μm using a ISI ArF excimerlaser with a NA=0.60 at a dose of 14.5 mJ/cm². After the exposure, thewafer was baked at 110° C. for 60 seconds and developed with an aqueousdeveloper AZ MIF 300 (tradename: available from Clariant Japan K.K.)containing 2.38% tetramethyl ammonium hydroxide for 60 seconds at 23° C.The material resolved 0.14 μm lines and space pattern without any T-topformation. The interface between the antireflective coating and thephotoresist was free of scum.

Example 243

Two solutions of negative-working chemically amplified radiationsensitive composition suitable for DUV (248 nm) exposure were preparedby mixing the following ingredients together:

7.9 g of a copolymer of 4-hydroxystyrene and styrene prepared by radicalpolymerization in the presence of2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) as a polymerizationinitiator, the copolymer having a molecular weight of 9,200 and apolydispersity of 2.14 as determined by GPC using polystyrene as thestandard and a monomer ratio of 8:2 as determined by ¹H-NMR,

2.0 g of distilled hexamethoxymethyl melamine,

0.3 g of tris-(4-t-butylphenyl) sulfonium nonafluorobutane sulfonate,

0.02 g of tetrabutyl ammonium lactate,

0.004 g of Megafac R-08 (tradename), and

62.4 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered, spin coated onto a HMDS treatedsilicon wafer at 3,000 rpm, and baked on a hot plate at 115° C. for 60seconds. The resulting film thickness was 0.72 μm. An exposure asdescribed in Example 201 followed at a dose of 32 mJ/cm². The exposedmaterial was then subjected to a post exposure bake on a hot plate at125° C. for 90 seconds and developed. The fine lines and spaces wereresolved down to 0.20 μm. Isolated lines were resolved down to 0.16 μmwhen a dose of 38 mJ/cm² was applied. The depth-of-focus of the 0.16 μmlines was about 0.80 μm.

Examples 244 and 245

A solution of negative-working chemically amplified radiation sensitivecomposition suitable for DUV (248 nm) and e-beam exposure was preparedby mixing the following ingredients together:

7.9 g of a copolymer of 4-hydroxystyrene and 4-methoxystyrene preparedby radical polymerization in the presence of2,2′-azobis(isobutyronitrile) as a polymerization initiator, thecopoylmer having a molecular weight of 9,600 and a polydispersity of2.21 as determined by GPC using polystyrene as the standard and amonomer ratio of 7.8:2.2 as determined by ¹H-NMR,

2.0 g of recrystallized tetramethoxymethyl glucoril,

0.5 g of tetrabutoxymethyl glucoril,

0.3 g of tris-(4-t-butylphenyl) sulfonium nonafluorobutane sulfonate,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

62.4 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered and spin coated onto two siliconwafers treated with an adhesion promoter (hexamethyl disilazane) at3,000 rpm. After baking on a hot plate at 95° C. for 60 seconds, a filmthickness of 0.74±0.2 μm was obtained. One wafer was subjected to anexposure through a mask with fine lines and space patterns down to 0.10μm using a Nikon NSR 2005 EX 10B KrF excimer laser stepper (NA=0.55,σ=0.80) at a dose of 24 mJ/cm². The other wafer was exposed with e-beamusing the e-beam writer described in Example 208 at a dose of 14.3μC/Cm². The exposed materials then were subjected to a post exposurebake on a hot plate at 95° C. for 90 seconds and developed.

The excimer laser exposed material resolved fine lines and spaces downto 0.20 μm. Isolated lines were resolved down to 0.15 μm when a dose of31 mJ/cm² was applied. The depth-of-focus of the 0.15 μm lines was about0.90 μm.

The e-beam exposed material yielded isolated lines with a linewidthbelow 0.10 μm.

Examples 246 and 247

Two solutions of a negative-working chemically amplified radiationsensitive composition suitable for DUV (248 nm) and x-ray exposure wereprepared by mixing the following ingredients together:

5.9 g of a terpolymer of 4-hydroxystyrene, styrene and N-hydroxymethylmethacrylamide with a molecular weight of 11,500, a polydispersity of1.69, and a monomer ratio of 8:1.8:0.2,

1.5 g of recrystallized tetramethoxymethyl glucoril,

0.5 g of 4,4′-(1-methylethylidene)-bis-[2,6-bis-(hydroxymethyl)-phenol]

0.3 g of bis-(t-butylphenyl) iodonium nonafluorobutane sulfonate,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

62.4 g of propylene glycol monomethyl ether acetate.

The solution thus obtained was filtered and spin coated onto two siliconwafers treated with an adhesion promoter (hexamethyl disilazane) at3,000 rpm. After baking on a hot plate at 95° C. for 60 seconds, a filmthickness of 0.67±0.02 μm was obtained. One of the wafers was subjectedto an exposure through a mask with fine lines and space patterns down to0.10 μm using a Nikon NSR 2005 EX 10B KrF excimer laser stepper(NA=0.55, σ=0.55) at a dose of 18 mJ/cm². The other wafer was exposedwith x-rays as described in Example 210 at a dose of 52 mJ/cm². Theexposed materials were then subjected to a post exposure bake on a hotplate at 95° C. for 90 seconds and developed.

The fine lines and spaces of the excimer laser exposed material wereresolved down to 0.22 μm. Isolated lines were resolved down to 0.18μwhen a dose of 25 mJ/cm²was applied. The depth-of-focus of the 0.18 μmlines was about 1.25 μm.

The x-ray exposed material resolved dense lines and spaces down to 0.16μm while isolated lines were resolved down below 0.16 μm.

Example 248 and Comparative Example 210

Two negative-working chemically amplified radiation sensitivecomposition solutions suitable for i-line (365 nm) exposure wereprepared by mixing the following ingredients together:

7.2 g of a copolymer (molecular weight 15,000, glass transitiontemperature 145° C.) of 3,5-dimethyl-4-hydroxystyrene and4-hydroxystyrene (3:7),

2.0 g of distilled hexamethoxymethyl melamine,

0.02 g of tetramethyl ammonium hydroxide,

0.004 g of Megafac R-08 (tradename), and

42.4 g of propylene glycol monomethyl ether acetate.

To one of the base formulations, a solution of 0.35 g of(4-phenyl-thiophenyl) diphenyl sulfonium nonafluorobutane sulfonatedissolved in 20 g of propylene glycol monomethyl ether acetate was added(Example 248), while to the other base formulation,

0.35 g of (4-phenyl-thiophenyl) diphenyl sulfonium trifluoromethanesulfonate dissolved in 20 g of propylene glycol monomethyl ether acetatewas added (Comparative Example 210). The solutions thus obtained werefiltered and spin coated onto HMDS treated silicon wafers at 2,400 rpm.After baking on a hot plate at 90° C. for 60 seconds, both materialsyielded a film thickness of 1.06±0.03 μm.

The wafers were subjected to an exposure through a mask with fine linesand space patterns down to 0.20 μm using a Nikon NSR 1755i 7a i-linestepper at a dose of 82 mJ/cm². The exposed materials were then baked ona hot plate at 105° C. for 90 seconds and developed.

The material of the Example 248 resolved 0.28 μm lines and spacespatterns and the profile of the resist patterns were ideallyrectangular. No whisker-like raised portions or scum were observed. Thedose to print isolated lines with a width of 0.28 μm was found to be 91mJ/cm².

The material of the Comparative Example 210 also resolved 0.28 μm linesand spaces patterns. However, the top of the line patterns was rounded,and the bottom of the line patterns had an undercut structure combinedwith severe scum. The dose to print isolated lines with a width of 0.28μm was found to be 95 mJ/cm²and therefore this formulation (ComparativeExample 210) was judged to be clearly inferior to that of the Example248.

Example 249 and Comparative Example 211

From Example 204, it is evident that the replacement of triflate basedPAGs with the nonaflate based PAGs of the present invention yieldsradiation sensitive compositions with identical sensitivity andresolution capability.

A first quartz wafer was coated with a solution containing a mixture of

5.0 g of poly-(4-hydroxystyrene), and

0.3 g of tris-(4-t-butylphenyl)sulfonium nonafluorobutane sulfonatedissolved in 50 g of propylene glycol monomethyl ether actetate andbaked at 120° C. for 60 seconds(Example 249, wafer 201).

A second quartz wafer was coated with a solution containing a mixture of

5.1 g poly-(4-hydroxystyrene), and

0.3 g tris-(4-t-butylphenyl)sulfonium triflate dissolved in 50 gpropylene glycol monomethyl ether acetate and baked at 120° C. for 60seconds (Comparative Example 211, wafer 202).

In addition, two other quartz wafers were coated with a solution of

5.0 g poly-(4-t-butyloxycarbonyloxystyrene) dissolved in 50 g propyleneglycol monomethyl ether acetate and baked at 90° C. for 90 seconds(wafer 203 and wafer 204). Wafers 203 and 204 were subjected to aquantitative FIR spectrum analysis with respect to the absorptionintensity of the carbonyl bond. Then the film on wafer 203 was broughtinto intimate contact with the film on wafer 201 and the film on wafer204 with the film on wafer 202 each at a pressure of about 0.05 kg/cm².Both wafer pairs were subjected to a flood irradiation with DUV KrFexcimer laser irradiation at a dose of 80 mJ/cm² and baked at 90° C. for90 seconds with wafers 203 and 204 on the upper side. The wafers 203 and204 were separated from wafers 201 and 202 and their FIR spectra wereagain recorded. After substraction of the two spectra (before and afterexposure/bake), it became evident that 47% of the t-butyloxycarbonyloxygroups of the polymer on wafer 204 had been cleaved into hydroxy groupsby trifluoromethanesulfonic acid produced during exposure and diffusinginto the polymer during the post exposure bake, while only 14% of thet-butyloxycarbonyloxy groups of the polymer on wafer 203 had beencleaved, indicating that the trifluoromethane sulfonic acid producedfrom wafer 202 was much more volatile than the nonafluorobutane sulfonicacid produced from wafer 201. From this experiment, it can be concludedthat the amount of acidic, corrosive and volatile products which mightcause destruction of the irradiation equipment and pose hazards to thehealth of the workers is significantly reduced, when triflate generatingPAGs were replaced with the PAGs of the present invention.

Example 250

The radiation sensitive composition of Example 241 was coated on amechanically surface grained aluminum foil and dried to a weight ofabout 1.2 g/m². After imagewise exposure through a positive-workingoriginal with a 5 kW metal halide light source for 23 seconds, the foilwas heated at 100° C. for 8 minutes in a convection oven. The printedimage was developed with a developer solution containing the followingingredients by a splush paddle method:

5.0 g of sodium lauryl sulfate,

1.5 g of sodium metasilicate pentahydrate,

1.6 g of trisodium phosphate dodecahydrate, and

92.5 g of ion-exchanged water.

The plate was then rinsed with pure water and dried. Step 6 of asilver-film continuous-tone step having a density range from 0.05 to3.05 and density increments of 0.15 was completely reproduced on thecopy. Even the finest screens and lines of the original were clearlyvisible. The printing plate obtained in the manner described gave 32,000high quality impressions on a sheetfed offset printing machine.

What is claimed is:
 1. A chemically amplified radiation sensitivecomposition comprising: an onium salt precursor, which generates afluorinated alkanesulfonic acid, as a photoacid generator, wherein thealkanesulfonic acid has 4 carbon atoms, and wherein the onium saltprecursor which generates a fluorinated alkanesulfonic acid is asulfonium or iodonium salt of nonafluorobutane sulfonate, and whereinthe photoacid generator is a sulfonium or iodonium salt of a fluorinatedalkane sulfonic acid, represented by formula (I): Y⁺ASO₃ ⁻  (I) whereinA represents CF₃CF₂CF₂CF₂; and Y represents

wherein R¹, R², R³, R⁴, and R⁵ each independently represent an alkylgroup, a monocyclic or bicyclic alkyl group, a cyclic alkylcarbonylgroup, a naphthyl group, an anthryl group, a peryl group, a pyryl group,a thienyl group, an aralkyl group, or an arylcarbonylmethylene group, orany two of R¹, R², and R³ or R⁴ and R⁵ together represent an alkylene oran oxyalkylene which forms a five- or six-membered ring together withthe interposing sulfur or iodine, said ring being optionally condensedwith aryl groups, one or more hydrogen atoms of R¹, R², R³, R⁴, and R⁵being optionally substituted by one or more groups selected from thegroup consisting of a halogen atom, an alkyl group, a cyclic alkylgroup, an alkoxy group, a cyclic alkoxy group, a dialkylamino group, acyclic dialkylamino group, a hydroxyl group, a cyano group, a nitrogroup, an aryl group, an aryloxy group, an arylthio group, and groups offormulae (II) to (VI):

wherein R⁶ and R⁷ each independently represent a hydrogen atom, an alkylgroup, which may be substituted by one or more halogen atoms, or acyclic alkyl group, which may be substituted by one or more halogenatoms, or R⁶ and R⁷ together can represent an alkylene group to form aring, R⁸ represents an alkyl group, a cyclic alkyl group, or an aralkylgroup, or R⁶ and R⁸ together represent an alkylene group which forms aring together with the interposing —C—O— group, the carbon atom in thering being optionally substituted by an oxygen atom, R⁹ represents analkyl group or a cyclic alkyl group, one or two carbon atoms in thealkyl group or the cyclic alkyl group being optionally substituted by anoxygen atom, an aryl group, or an aralkyl group, R¹⁰ and R¹¹ eachindependently represent a hydrogen atom, an alkyl group, or a cyclicalkyl group, R¹² represents an alkyl group, a cyclic alkyl group, anaryl group, or an aralkyl group, and R¹³ represents an alkyl group, acyclic alkyl group, an aryl group, an aralkyl group, the group—Si(R¹²)₂R¹³, or the group —O—Si(R¹²)₂R¹³; and a film forminghydroxystyrene based resin, wherein said film forming hydroxystyrenebased resin is a polymer of 4-hydroxystyrene, 3-hydroxystyrene, or2-hydroxystyrene, or a co-, ter-, quarter- or pentapolymer of thestyrenes and other monomers, or wherein said film forming hydroxystyreneresin that is a polymer of 4hydroxystyrene, 3-hydroxystyrene, or2-hydroxystyrene, or a co-, ter-, quarter- or pentapolymer of thestyrenes and other monomers, is made alkali insoluble by protectingalkali soluble groups on the resin with an acid cleavable protectinggroup.
 2. The composition according to claim 1, which is apositive-working chemically amplified radiation sensitive composition.3. The composition according to claim 2, wherein said resin has multipleacid cleavable C—O—C or C—O—Si bonds.
 4. The composition according toclaim 2, wherein said resin has a molecular weight of 2,000 to 200,000and a polydispersity of 1.01 to 2.80.
 5. The composition according toclaim 2, which further comprises a dissolution inhibitor with at leastone acid cleavable C—O—C or C—O—Si bond.
 6. The composition according toclaim 5, wherein said dissolution inhibitor is a phenolic and/orcarboxylic acid type compound with at least one acid cleavable C—O—C orC—O—Si bond and having a molecular weight of approximately 100 to20,000.
 7. The composition according to claim 2, which further comprisesother performance improving additives.
 8. A composition which comprises:(1) 0.1 to 30 parts by weight of a sulfonium or iodonium salt of afluorinated alkane sulfonic acid, represented by formula (I) of claim 1;(2) 100 parts by weight of said film forming hydroxystyrene based resinof claim 1, with multiple acid cleavable C—O—C or C—O—Si bonds; (3) 0 to50 parts by weight of a dissolution inhibitor with at least one acidcleavable C—O—C or C—O—Si bond; and (4) 0.01 to 5.0 parts by weight of aperformance improving additive.
 9. The composition according to claim 1,which is a negative-working chemically amplified radiation sensitivecomposition.
 10. The composition according to claim 9, wherein said filmforming hydroxystyrene based resin is an alkali soluble andacid-sensitive self-crosslinkable resin.
 11. The composition accordingto claim 9, which further comprises an acid-sensitive crosslinkingagent.
 12. The composition according to 11, wherein said crosslinkingagent is a melamine/formaldehyde condensate and/or a urea/formaldehydecondensate with at least two acid-crosslinkable groups.
 13. Thecomposition according to claim 9, wherein said resin has a molecularweight of 2,000 to 200,000 and a polydispersity of 1.01 to 2.80.
 14. Thecomposition according to claim 9, which further comprises otherperformance improving additives.
 15. The composition according to claim14, which comprises: (1) 0.1 to 30 parts by weight of a sulfonium oriodonium salt of a fluorinated alkane sulfonic acid, represented byformula (I); (2) 100 parts by weight of said hydroxystyrene based resin;(3) 3 to 70 parts by weight of an acid-sensitive crosslinking agent; and(4) 0.01 to 5.0 parts by weight of said performance improving additives.16. The composition according to claim 1, wherein said radiationsensitive photoacid generator is a compound of formula (I), where R¹,R², R³, R⁴, and R⁵ each independently represent a C₁₋₁₂ alkyl group, aC₆₋₁₂ monocyclic or bicyclic alkyl group, a C₄₋₁₂ cyclic alkylcarbonylgroup, a naphthyl group, an anthryl group, a peryl group, a pyryl group,a thienyl group, an aralkyl group, or an arylcarbonylmethylene groupwith up to 15 carbon atoms, or any two of R¹, R², and R³, or R⁴ and R⁵together represent an alkylene or an oxyalkylene which forms a five- orsix-membered ring together with the interposing sulfur or iodine atom,said ring being optionally condensed with aryl groups.
 17. Thecomposition according to claim 16, wherein said radiation sensitivephotoacid generator is a compound of formula (I), wherein one or morehydrogen atoms of R¹, R², R³, R⁴, and R⁵ are optionally substituted byat least one group selected from the group consisting of a halogen atom,a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, a C₁₋₆ alkoxy group, aC₃₋₆ cyclic alkoxy group, a di-C₁₋₃ alkylamino group, a cyclic di-C₆₋₁₂alkylamino group, a hydroxyl group, a cyano group, a nitro group, anaryloxy group, an arylthio group, and groups represented by formulae(II), (III), (IV), (V), and (VI), wherein R⁶ and R⁷ each independentlyrepresent a hydrogen atom, a C₁₋₆ alkyl group, which may be substitutedby one or more halogen atoms, or a C₃₋₆ cyclic alkyl group, which may besubstituted by one or more halogen atoms, or R⁶ and R⁷ togetherrepresent an alkylene group to form a five-membered or six-memberedring, R⁸ represents a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, or aC₇₋₁₂ aralkyl group, or R⁶ and R⁸ together represent an alkylene groupwhich forms a five- or six-membered ring together with the interposing—C—O— group, the carbon atom in the ring being optionally substituted byan oxygen atom, R⁹ represents a C₁₋₆ alkyl group or a C₃₋₆ cyclic alkylgroup, one or two carbon atoms in the alkyl group or the cyclic alkylgroup being optionally substituted by an oxygen atom, a C₆₋₁₂ arylgroup, or a C₇₋₁₂ aralkyl group, R¹⁰ and R¹¹ each independentlyrepresent a hydrogen atom, a C₁₋₆ alkyl group, or a C₃₋₆ cyclic alkylgroup, R¹² represents a C₁₋₆ alkyl group, a C₃₋₆ cyclic alkyl group, aC₆₋₁₂ aryl group, or a C₇₋₁₂ aralkyl group, and R¹³ represents a C₁₋₆alkyl group, a C₃₋₆ cyclic alkyl group, a C₆₋₁₂ aryl group, a C₇₋₁₂aralkyl group, group —Si(R¹²)₂R¹³, or group —O—Si(R¹²)₂R¹³.
 18. Thecomposition according to claim 1, wherein, in the compound of formula(I), R¹, R², R³, R⁴, and R⁵ each independently represent a C₁₋₃ alkylgroup, a C₃₋₆ monocyclic alkyl group, C₁₀₋₁₂ bicyclic alkyl group, aC₃₋₆ cyclic alkylcarbonyl group, or a naphthyl group, or any two of R¹,R² and R³, or R⁴ and R⁵ together represent an alkylene group to form afive- or six-membered alkylene ring, one or more hydrogen atoms of R¹,R², R³, R⁴, and R⁵ optionally substituted by at least one group selectedfrom the group consisting of a hydrogen atom, a halogen atom, a C₁₋₆alkyl group, a C₃₋₆ cyclic alkyl group, a C₁₋₆ alkoxyl group, a C₃₋₆cyclic alkoxyl group, a hydroxyl group, an aryloxy group, an arylthiogroup, and groups of formulae (II), (III), (IV), (V), and (VI), whereinR⁶ and R⁷ each independently represent either a hydrogen atom or amethyl group, provided that R⁶ and R⁷ do not simultaneously representhydrogen, R⁸ represents either a C₁₋₄ alkyl group or R⁶ and R⁸ togetherrepresent an alkylene group which forms a ring together with theinterposing —C—O— group, R⁹ represents a C₁₋₄ alkyl group, R¹⁰ and R¹¹represent a hydrogen atom, R¹² represents a methyl group, and R¹³represents a methyl group.
 19. An iodonium salt of formula (I) asdefined in claim
 1. 20. A sulfonium salt of formula (I) as defined inclaim 1, wherein at least one hydrogen atom on group represented by R¹,R², or R³ is substituted by a substituent defined in claim
 1. 21. Achemically amplified radiation sensitive composition comprising: anonium salt precursor, which generates a fluorinated alkanesulfonic acid,as a photoacid generator, wherein the alkanesulfonic acid has 3 carbonatoms, and wherein the onium salt precursor which generates afluorinated alkanesulfonic acid is a sulfonium or iodonium salt ofhexafluoropropane sulfonate, and wherein the photoacid generator is asulfonium or iodonium salt of a fluorinated alkane sulfonic acid,represented by formula (I): Y⁺ASO₃ ⁻  (I) wherein A representsCF₃CHFCF₂; and Y represents

wherein R¹, R², R³, R⁴, and R⁵ each independently represent an alkylgroup, a monocyclic or bicyclic alkyl group, a cyclic alkylcarbonylgroup, a phenyl group, a naphthyl group, an anthryl group, a perylgroup, a pyryl group, a thienyl group, an aralkyl group, or anarylcarbonylmethylene group, or any two of R¹, R², and R³ or R⁴ and R⁵together represent an alkylene or an oxyalkylene which forms a five- orsix-membered ring together with the interposing sulfur or iodine, saidring being optionally condensed with aryl groups, one or more hydrogenatoms of R¹, R², R³, R⁴, and R⁵ being optionally substituted by one ormore groups selected from the group consisting of a halogen atom, analkyl group, a cyclic alkyl group, an alkoxy group, a cyclic alkoxygroup, a dialkylamino group, a cyclic dialkylamino group, a hydroxylgroup, a cyano group, a nitro group, an aryl group, an aryloxy group, anarylthio group, and groups of formulae (II) to (VI):

wherein R⁶ and R⁷ each independently represent a hydrogen atom, an alkylgroup, which may be substituted by one or more halogen atoms, or acyclic alkyl group, which may be substituted by one or more halogenatoms, or R⁶ and R⁷ together can represent an alkylene group to form aring, R⁸ represents an alkyl group, a cyclic alkyl group, or an aralkylgroup, or R⁶ and R⁸ together represent an alkylene group which forms aring together with the interposing —C—O— group, the carbon atom in thering being optionally substituted by an oxygen atom, R⁹ represents analkyl group or a cyclic alkyl group, one or two carbon atoms in thealkyl group or the cyclic alkyl group being optionally substituted by anoxygen atom, an aryl group, or an aralkyl group, R¹⁰ and R¹¹ eachindependently represent a hydrogen atom, an alkyl group, or a cyclicalkyl group, R¹² represents an alkyl group, a cyclic alkyl group, anaryl group, or an aralkyl group, and R¹³ represents an alkyl group, acyclic alkyl group, an aryl group, an aralkyl group, the group—Si(R¹²)₂R¹³, or the group —O—Si(R¹²)₂R¹³; and a film forminghydroxystyrene based resin, wherein said film forming hydroxystyrenebased resin is a ter-, quarter- or pentapolymer of 4-hydroxystyrene,3-hydroxystyrene, or 2-hydroxystyrene, and other monomers, or whereinsaid film forming hydroxystyrene based resin that is a ter-, quarter- orpentapolymer of 4-hydroxystyrene, 3-hydroxystyrene, or 2-hydroxystyrene,and other monomers, is made alkali insoluble by protecting alkalisoluble groups on the resin with an acid cleavable protecting group. 22.The composition according to claim 21, which is a positive-workingchemically amplified radiation sensitive composition.
 23. Thecomposition according to claim 22, wherein said resin has multiple acidcleavable C—O—C or C—O—Si bonds.
 24. The composition according to claim22, wherein said resin has a molecular weight of 2,000 to 200,000 and apolydispersity of 1.01 to 2.80.
 25. The composition according to claim22, which further comprises a dissolution inhibitor with at least oneacid cleavable C—O—C or C—O—Si bond.
 26. The composition according toclaim 25, wherein said dissolution inhibitor is a phenolic and/orcarboxylic acid type compound with at least one acid cleavable C—O—C orC—O—Si bond and having a molecular weight of approximately 100 to20,000.
 27. The composition according to claim 22, which furthercomprises other performance improving additives.
 28. A composition whichcomprises: (1) 0.1 to 30 parts by weight of a sulfonium or iodonium saltof a fluorinated alkane sulfonic acid, represented by formula (I) ofclaim 21; (2) 100 parts by weight of said film forming hydroxystyrenebased resin of claim 21, with multiple acid cleavable C—O—C or C—O—Sibonds; (3) 0 to 50 parts by weight of a dissolution inhibitor with atleast one acid cleavable C—O—C or C—O—Si bond; and (4) 0.01 to 5.0 partsby weight of a performance improving additive.
 29. The compositionaccording to claim 21, which is a negative-working chemically amplifiedradiation sensitive composition.
 30. The composition according to claim29, wherein said film forming hydroxystyrene based resin is an alkalisoluble and acid-sensitive self-crosslinkable resin.
 31. The compositionaccording to claim 29, which further comprises an acid-sensitivecrosslinking agent.
 32. The composition according to 31, wherein saidcrosslinking agent is a melamine/formaldehyde condensate and/or aurea/formaldehyde condensate with at least two acid-crosslinkablegroups.
 33. The composition according to claim 29, wherein said resinhas a molecular weight of 2,000 to 200,000 and a polydispersity of 1.01to 2.80.
 34. The composition according to claim 29, which furthercomprises other performance improving additives.
 35. A composition whichcomprises: (1) 0.1 to 30 parts by weight of a sulfonium or iodonium saltof a fluorinated alkane sulfonic acid, represented by formula (I) ofclaim 21; (2) 100 parts by weight of said film forming hydroxystyrenebased resin of claim 21; (3) 3 to 70 parts by weight of anacid-sensitive crosslinking agent; and (4) 0.01 to 5.0 parts by weightof a performance improving additive.
 36. The composition according toclaim 21, wherein said radiation sensitive photoacid generator is acompound of formula (I), where R¹, R², R³, R⁴, and R⁵ each independentlyrepresent a C₁₋₁₂ alkyl group, a C₆₋₁₂ monocyclic or bicyclic alkylgroup, a C₄₋₁₂ cyclic alkylcarbonyl group, a phenyl group, a naphtylgroup, an anthryl group, a peryl group, a pyryl group, a thienyl group,an aralkyl group, or an arylcarbonylmethylene group with up to 15 carbonatoms, or any two of R¹, R², and R³, or R⁴ and R⁵ together represent analkylene or an oxyalkylene which forms a five- or six-membered ringtogether with the interposing sulfur or iodine atom, said ring beingoptionally condensed with aryl groups.
 37. The composition according toclaim 36, wherein said radiation sensitive photoacid generator is acompound of formula (I), wherein one or more hydrogen atoms of R¹, R²,R³, R⁴, and R⁵ are optionally substituted by at least one group selectedfrom the group consisting of a halogen atom, a C₁₋₆ alkyl group, a C₃₋₆cyclic alkyl group, a C₁₋₆ alkoxy group, a C₃₋₆ cyclic alkoxy group, adi-C₁₋₃ alkylamino group, a cyclic di-C₆₋₁₂ alkylamino group, a hydroxylgroup, a cyano group, a nitro group, an aryl group, an aryloxy group, anarylthio group, and groups represented by formulae (II), (III), (IV),(V), and (VI), wherein R⁶ and R⁷ each independently represent a hydrogenatom, a C₁₋₆ alkyl group, which may be substituted by one or morehalogen atoms, or a C₃₋₆ cyclic alkyl group, which may be substituted byone or more halogen atoms, or R⁶ and R⁷ together represent an alkylenegroup to form a five-membered or six-membered ring, R⁸ represents a C₁₋₆alkyl group, a C₃₋₆ cyclic alkyl group, or a C₇₋₁₂ aralkyl group, or R⁶and R⁸ together represent an alkylene group which forms a five- orsix-membered ring together with the interposing —C—O— group, the carbonatom in the ring being optionally substituted by an oxygen atom, R⁹represents a C₁₋₆ alkyl group or a C₃₋₆ cyclic alkyl group, one or twocarbon atoms in the alkyl group or the cyclic alkyl group beingoptionally substituted by an oxygen atom, a C₆₋₁₂ aryl group, or a C₇₋₁₂aralkyl group, R¹⁰ and R¹¹ each independently represent a hydrogen atom,a C₁₋₆ alkyl group, or a C₃₋₆ cyclic alkyl group, R¹² represents a C₁₋₆alkyl group, a C₃₋₆ cyclic alkyl group, a C₆₋₁₂ aryl group, or a C₇₋₁₂aralkyl group, and R¹³ represents a C₁₋₆ alkyl group, a C₃₋₆ cyclicalkyl group, a C₆₋₁₂ aryl group, a C₇₋₁₂ aralkyl group, group—Si(R¹²)₂R¹³, or group —O—Si(R¹²)₂R¹³.
 38. The composition according toclaim 21, wherein, in the compound of formula (I), R¹, R², R³, R⁴, andR⁵ each independently represent a C₁₋₃ alkyl group, a C₃₋₆ monocyclicalkyl group, C₁₀₋₁₂ bicyclic alkyl group, a C₃₋₆ cyclic alkylcarbonylgroup, a phenyl group, or a naphthyl group, or any two of R¹, R² and R³,or R⁴ and R⁵ together represent an alkylene group to form a five- orsix-membered alkylene ring, one or more hydrogen atoms of R¹, R², R³,R⁴, and R⁵ optionally substituted by at least one group selected fromthe group consisting of a hydrogen atom, a halogen atom, a C₁₋₆ alkylgroup, a C₃₋₆ cyclic alkyl group, a C₁₋₆ alkoxyl group, a C₃₋₆ cyclicalkoxyl group, a hydroxyl group, an aryl group, an aryloxy group, anarylthio group, and groups of formulae (II), (III), (IV), (V), and (VI),wherein R⁶ and R⁷ each independently represent either a hydrogen atom ora methyl group, provided that R⁶ and R⁷ do not simultaneously representhydrogen, R⁸ represents either a C₁₋₄ alkyl group or R⁶ and R⁸ togetherrepresent an alkylene group which forms a ring together with theinterposing —C—O— group, R⁹ represents a C₁₋₄ alkyl group, R¹⁰ and R¹¹represent a hydrogen atom, R¹² represents a methyl group, and R¹³represents a methyl group.
 39. The composition according to claim 21,wherein said compound of formula (I) is atris-(4-t-butylphenyl)sulfonium salt of a fluorinated alkane sulfonate.]40. An iodonium salt of formula (I) as defined in claim
 21. 41. Asulfonium salt of formula (I) as defined in claim 21, wherein at leastone hydrogen atom on group represented by R¹, R², or R³ is substitutedby a substituent defined in claim
 21. 42.Tris-(4-t-butylphenyl)sulfonium 3,3,3,2,1,1-hexafluoropropane sulfonate.